diff --git a/unit_test/CMakeLists.txt b/unit_test/CMakeLists.txt
index b97153e..fa57558 100644
--- a/unit_test/CMakeLists.txt
+++ b/unit_test/CMakeLists.txt
@@ -48,6 +48,6 @@ macro(CabanaPD_add_tests)
   endforeach()
 endmacro()
 
-CabanaPD_add_tests(NAMES Force Integrator)
+CabanaPD_add_tests(NAMES Particles Force Integrator)
 
 CabanaPD_add_tests(MPI NAMES Comm)
diff --git a/unit_test/tstParticles.hpp b/unit_test/tstParticles.hpp
new file mode 100644
index 0000000..ea38387
--- /dev/null
+++ b/unit_test/tstParticles.hpp
@@ -0,0 +1,140 @@
+/****************************************************************************
+ * Copyright (c) 2022 by Oak Ridge National Laboratory                      *
+ * All rights reserved.                                                     *
+ *                                                                          *
+ * This file is part of CabanaPD. CabanaPD is distributed under a           *
+ * BSD 3-clause license. For the licensing terms see the LICENSE file in    *
+ * the top-level directory.                                                 *
+ *                                                                          *
+ * SPDX-License-Identifier: BSD-3-Clause                                    *
+ ****************************************************************************/
+
+#include <gtest/gtest.h>
+
+#include <Cabana_Core.hpp>
+#include <Kokkos_Core.hpp>
+
+#include <CabanaPD_Particles.hpp>
+
+namespace Test
+{
+template <typename ParticlesType>
+void checkNumParticles( const ParticlesType& particles,
+                        const std::size_t expected_frozen,
+                        const std::size_t expected_local,
+                        const std::size_t expected_ghost = 0 )
+{
+    // Check the values.
+    auto frozen = particles.numFrozen();
+    EXPECT_EQ( frozen, expected_frozen );
+    auto local = particles.numLocal();
+    EXPECT_EQ( local, expected_local );
+    auto ghost = particles.numGhost();
+    EXPECT_EQ( ghost, expected_ghost );
+
+    // Check the offsets.
+    EXPECT_EQ( particles.frozenOffset(), expected_frozen );
+    EXPECT_EQ( particles.localOffset(), expected_frozen + expected_local );
+    EXPECT_EQ( particles.referenceOffset(),
+               expected_frozen + expected_local + expected_ghost );
+}
+
+template <typename ParticlesType>
+void checkParticlePositions( const ParticlesType& particles,
+                             const std::array<double, 3> box_min,
+                             const std::array<double, 3> box_max,
+                             const std::size_t start, const std::size_t end )
+{
+    using HostAoSoA = Cabana::AoSoA<Cabana::MemberTypes<double[3], double>,
+                                    Kokkos::HostSpace>;
+    HostAoSoA aosoa_host( "host_aosoa", particles.referenceOffset() );
+    auto x_host = Cabana::slice<0>( aosoa_host );
+    auto x = particles.sliceReferencePosition();
+    Cabana::deep_copy( x_host, x );
+
+    // Check the particles were created in the right box.
+    for ( std::size_t p = start; p < end; ++p )
+        for ( int d = 0; d < 3; ++d )
+        {
+            EXPECT_GE( x_host( p, d ), box_min[d] );
+            EXPECT_LE( x_host( p, d ), box_max[d] );
+        }
+}
+
+//---------------------------------------------------------------------------//
+void testCreateParticles()
+{
+    using exec_space = TEST_EXECSPACE;
+
+    std::array<double, 3> box_min = { -1.0, -1.0, -1.0 };
+    std::array<double, 3> box_max = { 1.0, 1.0, 1.0 };
+    std::array<int, 3> num_cells = { 10, 10, 10 };
+
+    // Frozen or all particles first.
+    CabanaPD::Particles<TEST_MEMSPACE, CabanaPD::PMB,
+                        CabanaPD::TemperatureIndependent>
+        particles( exec_space(), box_min, box_max, num_cells, 0 );
+
+    // Check expected values for each block of particles.
+    std::size_t expected_local = num_cells[0] * num_cells[1] * num_cells[2];
+    std::size_t expected_frozen = 0;
+
+    checkNumParticles( particles, expected_frozen, expected_local );
+    checkParticlePositions( particles, box_min, box_max,
+                            particles.frozenOffset(), particles.localOffset() );
+}
+
+void testCreateFrozenParticles()
+{
+    using exec_space = TEST_EXECSPACE;
+
+    std::array<double, 3> box_min = { -1.0, -1.0, -1.0 };
+    std::array<double, 3> box_max = { 1.0, 1.0, 1.0 };
+    std::array<int, 3> num_cells = { 10, 10, 10 };
+
+    // Frozen in bottom half.
+    auto init_bottom = KOKKOS_LAMBDA( const int, const double x[3] )
+    {
+        if ( x[2] < 0.0 )
+            return true;
+        return false;
+    };
+    CabanaPD::Particles<TEST_MEMSPACE, CabanaPD::PMB,
+                        CabanaPD::TemperatureIndependent>
+        particles( exec_space(), box_min, box_max, num_cells, 0, init_bottom, 0,
+                   true );
+
+    // Unfrozen in top half.
+    auto init_top = KOKKOS_LAMBDA( const int, const double x[3] )
+    {
+        if ( x[2] > 0.0 )
+            return true;
+        return false;
+    };
+    // Create more, starting from the current number of frozen points.
+    particles.createParticles( exec_space{}, init_top, particles.numFrozen() );
+
+    // Check expected values for each block of particles.
+    std::size_t expected_local = num_cells[0] * num_cells[1] * num_cells[2] / 2;
+    std::size_t expected_frozen = expected_local;
+    checkNumParticles( particles, expected_frozen, expected_local );
+
+    // Check frozen and local separately.
+    box_max[2] = 0.0;
+    checkParticlePositions( particles, box_min, box_max, 0,
+                            particles.frozenOffset() );
+    box_min[2] = 0.0;
+    box_max[2] = 1.0;
+    checkParticlePositions( particles, box_min, box_max,
+                            particles.frozenOffset(), particles.localOffset() );
+}
+
+//---------------------------------------------------------------------------//
+// TESTS
+//---------------------------------------------------------------------------//
+TEST( TEST_CATEGORY, test_create_local ) { testCreateParticles(); }
+TEST( TEST_CATEGORY, test_create_frozen ) { testCreateFrozenParticles(); }
+
+//---------------------------------------------------------------------------//
+
+} // end namespace Test