Cognomen Мрочек (Мрочек 
, Mroček 
, Mrochek 
) , all over the world, is a rare surname. The surname Мрочек is habitual in Belarus, where it is a rare surname, Croatia, and Lithuania. In absolute terms, the name is most common in the United States, Belarus, and Russia.
| VARIANT | COUNTRY |
|---|---|
| Мрочек | Russia, Ukraine, Belarus |
| Mroček | Croatia, Czechia |
| Mrochek | Russia, Belarus, United States, Canada, Lithuania |
| мрочек, вацлав ромуальдович UA (b. 1897) |
|