Cognomen Vaslav (Васлав 
, Vaslav 
, Нижинский 
) , in the entire world, is a rare family name. The family name Vaslav is habitual in Romania, where it is a rare surname, Russia, where it is a very rare surname, and Kyrgyzstan. Measured by absolute frequency, the name is most common in Russia, Romania, and India. Very seldom, Vaslav is the forename as well as the last name.