In 1995 Kostadinova gave birth to her son, Nikolay, just several months before winning gold in the 1995 World Championships in Athletics. In 1999 she divorced her long-standing husband and coach, Nikolay Petrov. The same year she officially put an end to her athletic career, though she had actually not participated in any major sports competition since the World Indoors Championship in 1997. In 2007 Kostadinova married her companion of some nine years, a businessman in the construction industry, Nikolai Popvasilev.