Former France midfielder Vieira took over in November last year when Genoa were 17th and helped the club avoid relegation, finishing 13th in the Italian top-flight. However, they made a dismal start to the new season, scoring four goals in nine matches.
"Genoa CFC announces that Patrick Vieira is no longer the coach of the first team... the technical leadership of the first team has been entrusted on an interim basis to Roberto Murgita, assisted by Domenico Criscito," the club said in a statement on Saturday.
Genoa, who are two points below the safety zone, visit Sassuolo on Monday.