Juventus launched an appeal after the Sweden international was banned using television evidence. The cameras appeared to show Ibrahimovic elbowing Inter Milan's Ivan Cordoba earlier this month.
A Serie A disciplinary committee upheld the suspension. Ibrahimovic will miss Sunday's home game against Bologna and the crucial meeting with Milan at the San Siro on May 8.
Milan and Juventus are locked together on 73 points at the top of the league with five matches left to play.
