Pernik, city in western Bulgaria, capital of Pernik Province, on the Struma River near Sofia. A road and rail junction and coal-mining centre since 1891, Pernik is located in an area containing many lignite mines and iron smelteries. Industries include engineering, and the manufacture of briquettes, electrical equipment, and glass. Ruins of a Byzantine fortress are located here. From 1949 to 1962 the city was called Dimitrovo. Population (1990 estimate) 99,643.