The incident occurred on October 3rd 2012 when the convicted man was 18, the court heard.
His mother discovered her son passed out in the bathroom of the family’s apartment in the city of Zurich after a bout of drinking, the German-language 20 Minuten newspaper reported online.
She dragged him into his bedroom and when he awoke he began to insult her, according to the court evidence.
She responded by slapping him and he reacted by punching her in the face, the newspaper reported.
He hit her on the nose, cheek bone and on the back of the head and the neck.
His father tried to intervene but the son then threatened to kill his mother and the whole family before the couple called police, 20 Minuten reported.
The son admitted to the allegations and burst into tears in the courtroom, the newspaper said.
The accused said he was repeatedly under stress and his parents had threatened to throw him out of the apartment.
However, the court heard the man had two previous criminal convictions and a psychiatrist testified that there was a “significant risk” of the man reoffending with violence.
The convicted man is to undergo therapy as part of his sentence.
In Switzerland, more than 200 cases of parents being attacked by their children were recorded last year, 20 Minuten said.
The actual number is likely much higher because many parents do not want to report such cases out of shame, one expert was quoted as saying.
Cases of violence against parents range from verbal threats, physical attacks and blackmail, Christine von Salis, co-director of an intervention centre against domestic violence in the canton of Basel-Country told 20 Minuten.
Parents who experience such problems should seek professional help, experts say.