diff --git a/htdocs/langs/mn_MN/main.lang b/htdocs/langs/mn_MN/main.lang
new file mode 100644
index 00000000000..34bf859ace5
--- /dev/null
+++ b/htdocs/langs/mn_MN/main.lang
@@ -0,0 +1,21 @@
+# Dolibarr language file - Source file is en_US - main
+DIRECTION=ltr
+FONTFORPDF=helvetica
+FONTSIZEFORPDF=10
+SeparatorDecimal=.
+SeparatorThousand=None
+FormatDateShort=%Y.%m.%d
+FormatDateShortInput=%Y.%m.%d
+FormatDateShortJava=yyyy.MM.dd
+FormatDateShortJavaInput=yyyy.MM.dd
+FormatDateShortJQuery=yy.mm.dd
+FormatDateShortJQueryInput=yy.mm.dd
+FormatHourShortJQuery=HH:MI
+FormatHourShort=%H:%M
+FormatHourShortDuration=%H:%M
+FormatDateTextShort=%d %b %Y
+FormatDateText=%d %B %Y
+FormatDateHourShort=%d/%m/%Y %H:%M
+FormatDateHourSecShort=%d/%m/%Y %H:%M:%S
+FormatDateHourTextShort=%d %b %Y %H:%M
+FormatDateHourText=%d %B %Y %H:%M