It happened at a house On Pinewood Green Road at around 8.40pm last night.
Gardaí say two men wearing balaclavas and armed with a shotgun rang the doorbell and fired two shots before escaping in a car.
Two women - one in her 30s, the other in her 40s - and a man in his 20s were wounded.
All three were taken to Beaumont Hospital, however their injuries are not believed to be life threatening.
Gardaí say three children and a fourth adult were in the house at the time.
Elsewhere, gardaí are investigating an incident in which a man received stab wounds to the head.
It happened at a flat in Ballymun at around 11.30pm.
The man's injuries are not thought to be serious.
