Background Hand and wrist pain can develop during the postpartum period, may be exacerbated by activities during childcare and may continue for several months, leading to chronic upper extremity disability. Little is known about the impact of hand and wrist pain on quality of life in postpartum mothers. Aims This study aimed to explore the relationship between self-assessed hand and wrist pain, upper extremity disability and quality of life among postpartum mothers in Japan. Methods A prospective cohort study was designed for women who had given birth at a general hospital and a clinic in the south of Japan. Participants self-assessed hand and wrist pain using Eichhoff's test and upper extremity disability using the Hand20 questionnaire. General quality of life was assessed with the EQ-5D-5L. Results Self-assessed hand and wrist pain was significantly associated with upper extremity disability. Self-reported subjective and induced pain was associated with lower quality of life. Conclusions Self-assessed hand and wrist pain in postpartum women can significantly lower quality of life. Reporting subjective and self-induced pain helps diagnosis of and may prevent disability, improving a mother's quality of life.