diff --git a/extensions/cstrike/natives.cpp b/extensions/cstrike/natives.cpp
index bc5e5e51..5d4bbfcb 100644
--- a/extensions/cstrike/natives.cpp
+++ b/extensions/cstrike/natives.cpp
@@ -862,6 +862,21 @@ static cell_t CS_UpdateClientModel(IPluginContext *pContext, const cell_t *param
 
 	return 1;
 }
+
+static cell_t CS_ItemDefIndexToID(IPluginContext *pContext, const cell_t *params)
+{
+#if SOURCE_ENGINE == SE_CSGO
+	ItemIndexMap::Result res = g_mapDefIdxToClass.find((uint16_t)params[1]);
+
+	if (!res.found())
+		return  pContext->ThrowNativeError("Invalid item definition passed.");
+
+	return res->value.m_iWeaponID;
+#else
+	return pContext->ThrowNativeError("CS_ItemDefIndexToID is not supported on this game");
+#endif
+}
+
 sp_nativeinfo_t g_CSNatives[] = 
 {
 	{"CS_RespawnPlayer",			CS_RespawnPlayer}, 
@@ -884,6 +899,7 @@ sp_nativeinfo_t g_CSNatives[] =
 	{"CS_SetClientAssists",			CS_SetClientAssists},
 	{"CS_UpdateClientModel",		CS_UpdateClientModel},
 	{"CS_IsValidWeaponID",			CS_IsValidWeaponID},
+	{"CS_ItemDefIndexToID",			CS_ItemDefIndexToID },
 	{NULL,							NULL}
 };
 
diff --git a/plugins/include/cstrike.inc b/plugins/include/cstrike.inc
index f2b40dad..a80103b5 100644
--- a/plugins/include/cstrike.inc
+++ b/plugins/include/cstrike.inc
@@ -391,6 +391,17 @@ native bool CS_IsValidWeaponID(CSWeaponID id);
  */
 native void CS_UpdateClientModel(int client);
 
+/**
+ * Returns a CSWeaponID equivalent based on the item definition index.
+ *
+ * @param ItemDefinitionIndex	Definition index to get the CSWeaponID value for.
+ * @return			Returns CSWeaponID value for the definition index.
+ * 
+ * @error			Invalid definition index.
+ * @note			In most cases the id will be the item definition index.
+ */
+native CSWeaponID CS_ItemDefIndexToID(int ItemDefinitionIndex);
+
 /**
  * Do not edit below this line!
  */
@@ -429,5 +440,6 @@ public void __ext_cstrike_SetNTVOptional()
 	MarkNativeAsOptional("CS_WeaponIDToAlias");
 	MarkNativeAsOptional("CS_IsValidWeaponID");
 	MarkNativeAsOptional("CS_UpdateClientModel");
+	MarkNativeAsOptional("CS_ItemDefIndexToID");
 }
 #endif