Cognomen Mermelshteyn (Mermelshteyn 
, Мермельштейн 
) , in the entire world, is a very rare family name. The family name Mermelshteyn is habitual in Eastern Europe, particularly Hungary, where it is a rare surname, Russia, where it is a very rare surname, and Ukraine, where it is an extremely rare surname. Measured by absolute frequency, it most frequently occurs in Russia, Hungary, and the United States.
| VARIANT | COUNTRY |
|---|---|
| Mermelshteyn | United States, Hungary |
| Мермельштейн | Russia, Ukraine |