Surname Ejsak (Ejsak 
, Эйсак 
) , in the entire world, is a rare cognomen. The cognomen Ejsak is habitual in Belarus, where it is quite a rare surname, Estonia, where it is a rare surname, and Poland. Not in comparison with a country's population, this name is the most popular in Eastern Europe, particularly Belarus, Poland, and Russia. Much less frequently, Ejsak is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Ejsak | Poland, Germany, Belarus, Estonia |
| Эйсак | Kazakhstan, Russia, Belarus |