Internacional sack Falcao after three months
"The decision came about for a number of factors," club president Giovanni Luigi was quoted as telling a news conference on their website.
"I understand we weren't getting results and the [team's] performances were unsatisfactory. It was a decision that had to be taken, it was time to make a change."
He added that the new coach and the club's new director of football would be named by Wednesday at the latest.
Former Brazil midfielder and Internacional idol Falcao was appointed in mid-April after Celso Roth, who steered the Reds to their second South American Libertadores Cup victory last year, was sacked.
Under Roth, Inter failed in December to regain the Club World Cup title they had won in 2006 when they became the first team from outside Europe or South America to fall in the semi-finals, beaten by African champions TP Mazembe of the Democratic Republic of Congo.
Results under Falcao have been mixed and his sacking comes after three successive defeats in the Brazilian Championship where Inter are eighth with 15 points from 11 matches.