当年,白中发(杜汶泽 饰)与皇天霸(李国煌 饰)师从于麻雀至尊儒五常(曾志伟 饰),白中发天性淡泊,学到了儒五常的麻雀精髓,而皇天霸争强好胜,后终与师父、师兄决裂。二十多年后,白中发与女儿四喜开饭馆度日。连续获得十界麻雀王大赛冠军的皇天霸不甘心首届“麻雀王”桂冠被白中发赢得,时时策划在麻将桌上赢下师兄。另一方面,曾经抛弃白中发父女二人的梦娜(叶璇 饰)突然出现,原来梦娜爱慕虚荣,不能忍受夺得麻雀王称号的白中发退隐,遂丢下襁褓中的四喜离去。但梦娜的这次归来并非单纯为了找回丈夫和女儿,其背后有着皇天霸的指使,师兄弟的麻雀对决一触即发……A family comedy set in modern times, KING OF MAHJONG illustrates how friendship among kampong kakis ("buddies") and love between family members underscore all ambitions and desire for power. Movie viewers can expect the boisterous characters to generate loads of witty, well-timed, jokes and look forward to lots of lively repartee.