衣厂女工冯英好打不平，勇武过人，被称为沙胆英，与工厂女工陈芳、李细珠结为金兰姊妹，三人严惩歹徒，为工友出头，大快人心，但却同时得罪了黑道大鸡陆，而大鸡陆手下刘伟原来是沙胆英的旧情人；当沙胆英落入大鸡陆的魔掌，性命岌岌可危之际，陈芳、细珠等女工及大哥成等赶来，与大阿哥大战一番。最後，刘伟牺牲自己，才将沙胆英营救出险

Ah Ying (Chen Ping) is a former gangster trying to lead an honest life, and occasionally using her fighting skills to help out the girls in the factory where she now works. She befriends young colleagues Chong Lee and Shao Yin-Yin, teaching them self defence because "girls can't be weak anymore". Trouble starts when her old gang finds out where she now works.