diff --git a/MdeModulePkg/Bus/Scsi/ScsiBusDxe/ScsiBus.c b/MdeModulePkg/Bus/Scsi/ScsiBusDxe/ScsiBus.c
index 8eb73e7673..b10e25a38e 100644
--- a/MdeModulePkg/Bus/Scsi/ScsiBusDxe/ScsiBus.c
+++ b/MdeModulePkg/Bus/Scsi/ScsiBusDxe/ScsiBus.c
@@ -1007,9 +1007,10 @@ ScsiExecuteSCSICommand (
                                                 ExtRequestPacket,
                                                 NULL
                                                 );
-      if (Event != NULL) {
+      if ((!EFI_ERROR(Status)) && (Event != NULL)) {
         //
-        // Signal Event to tell caller to pick up the SCSI IO Packet.
+        // Signal Event to tell caller to pick up the SCSI IO packet if the
+        // PassThru() succeeds.
         //
         gBS->SignalEvent (Event);
       }