diff --git a/fs/nxffs/nxffs_truncate.c b/fs/nxffs/nxffs_truncate.c
new file mode 100644
index 0000000000..c8e92c0b48
--- /dev/null
+++ b/fs/nxffs/nxffs_truncate.c
@@ -0,0 +1,138 @@
+/****************************************************************************
+ * fs/nxffs/nxffs_truncate.c
+ *
+ *   Copyright (C) 2018 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * References: Linux/Documentation/filesystems/romfs.txt
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <fcntl.h>
+#include <assert.h>
+#include <errno.h>
+#include <debug.h>
+
+#include <nuttx/semaphore.h>
+
+#include "nxffs.h"
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: nxffs_truncate
+ *
+ * Description:
+ *   Set the length of the open, regular file associated with the file
+ *   structure 'filep' to 'length'.
+ *
+ ****************************************************************************/
+
+int nxffs_truncate(FAR struct file *filep, off_t length)
+{
+  FAR struct nxffs_volume_s *volume;
+  FAR struct nxffs_wrfile_s *wrfile;
+  off_t oldsize;
+  int ret;
+
+  finfo("Write %d bytes to offset %d\n", buflen, filep->f_pos);
+
+  /* Sanity checks */
+
+  DEBUGASSERT(filep->f_priv != NULL && filep->f_inode != NULL);
+
+  /* Recover the open file state from the struct file instance */
+
+  wrfile = (FAR struct nxffs_wrfile_s *)filep->f_priv;
+
+  /* Recover the volume state from the open file */
+
+  volume = (FAR struct nxffs_volume_s *)filep->f_inode->i_private;
+  DEBUGASSERT(volume != NULL);
+
+  /* Get exclusive access to the volume.  Note that the volume exclsem
+   * protects the open file list.
+   */
+
+  ret = nxsem_wait(&volume->exclsem);
+  if (ret < 0)
+    {
+      ferr("ERROR: nxsem_wait failed: %d\n", ret);
+      goto errout;
+    }
+
+  /* Check if the file was opened with write access */
+
+  if ((wrfile->ofile.oflags & O_WROK) == 0)
+    {
+      ferr("ERROR: File not open for write access\n");
+      ret = -EACCES;
+      goto errout_with_semaphore;
+    }
+
+  /* Are we shrinking the file?  Or extending it? */
+
+  oldsize = wrfile->ofile.entry.datlen;
+  if (oldsize == length)
+    {
+      ret = OK;
+      goto errout_with_semaphore;
+    }
+  else if (oldsize > length)
+    {
+      /* We are shrinking the file */
+      /* REVISIT:  Logic to shrink the file has not yet been implemented */
+
+      ret = -ENOSYS;
+    }
+  else
+    {
+      /* We are zero-extending the file.  This essential amount to a write-
+       * append operation with zero data.
+       */
+
+      ret = nxffs_wrextend(volume, wrfile, length);
+    }
+
+errout_with_semaphore:
+  nxsem_post(&volume->exclsem);
+
+errout:
+  return ret;
+}
+