大学毕业生天翔（张学友 饰）出身贫寒，其父猜叔（董骠 饰）靠在榕树头卖唱养活天翔以及年幼的一子一女，天翔不愿父亲在市场唱黄色小曲挣钱，但无奈工资微薄，只得在同事的侧目中忍受。天翔在工作中踏实肯干，在好友大傻（刘青云 饰）的帮助下为公司立下功劳，同时大老板的妹妹比蒂（周海媚 饰）对天翔也颇为有意，二人感情渐浓之际，大老板却因天翔一家的地位低下而中断了这段姻缘，天翔只得从相邻的舞女周枫（张曼玉 饰）处获得情感慰藉。失去工作的天翔加入黑道团伙，与大傻一起同另一势力高佬森连番拼杀，高佬森一伙将大傻和周枫害死，天翔向高佬森寻仇之际，猜叔为保全儿子挺身而出……

Peter Ho (Jacky Cheung) is a low-level employee at a prestigious firm in Central, but he hides a secret from his stodgy bosses. Peter's family is exceptionally poor, and his father (Bill Tung Piu) is actually an infamous street performer who sings off-color songs for donations on the street. Peter manages to progress in his job, and even begins to date his boss' daughter. But when the truth of his background is discovered, Peter is summarily fired. Bitter and angry, Peter joins the triads along with his pal (Sean Lau Ching Wan), and finds new romance with the luminous Maggie Cheung. When given the chance, Peter even uses his new underworld position to threaten his previous boss! But Peter sinks too far into the triad underworld, and soon not even his family can be spared from violence. A harrowing drama that progresses from social critique to triad indictment, My Dear Son runs the full gamut of emotions to deliver a tough and truthful message about the choices we make in life.