The wedding procession was on its way to Charsadda town in Khyber-Pakhtunkhwa province when the vehicle fell into the canal at Chargano Killey.
The canal was swollen following heavy rains and several people were swept away.
Rescue teams retrieved 19 bodies from the canal and took eight injured persons to Lady Reading Hospital in Peshawar.
Officials described the condition of some of the injured as critical.
Five women were among the dead.
Police official Javed Khan told the media that 35 people were in the mini-bus.