The male tiger, Kesha, was ordered to perform a trick, but instead lifted one of his hind legs and urinated on the people in the best seats, a Kazakh news website reported.
Several kids and adults were hit by the urine stream, causing the show to be halted by laughter.
However, the performance proceeded after the people wiped themselves clean with handkerchiefs, the news website said.
No complaints were filed against Kesha or the circus owners. The Nikulin Moscow Circus was in the second week of its shows in Ekibastuz in northeastern Kazakhstan.