Kostomarov began skating at the age of nine and a coach put him in ice dancing at eleven.

[7] In 2008, Kostomarov played the role of figure skater Viktor Molodtsov in the TV series Hot Ice.

Kostomarov married Austrian ladies' champion Julia Lautowa in June 2004.

In April 2014, he married Russian ice dancer Oksana Domnina.

[15] On February 6, 2023, an operation was performed, the purpose of which was to remove necrosis and stop the process of cell death.

[17] (with Navka) GP: part of Champions Series from 1995; renamed Grand Prix in 1998.