The fire broke out in the attic of the building of the School of Modern Drama theatre in central Moscow.
More than 350 people were evacuated from the building, Moscow law enforcement agencies told ITAR-TASS.
Several fire trucks were fighting the fire.
"According to preliminary reports, the two-story theatre building situated in Neglinnaya Street has an area of 500 square metres. The storeys in the theatre are (being) strongly fumigated," a source in the Moscow law enforcement agencies said.
According to the ministry of emergency situations, the wooden ceilings between the second floor and the attic caught fire.
The fire department headquarter has been informed and the fire has been rated at the second degree on a five-point fire scale.
According to the source, the roof of the theatre collapsed partially.