Characteristics of menstruation and reproductive history were studied in 2331 Caucasian, 4097 Japanese and 1003 Chinese women living in Hawaii and born between 1900 and 1940. Irregular periods, heavy flow and menses lasting more than five days were reported significantly more often in Caucasians than in the other two groups. Canonical correlation and multiple-regression procedures revealed that parity, recalled age at menarche and year of birth were significantly associated to the menstrual descriptions reported, in complex ways, distinctive in each ethnic group. Some similarities in the relationship of reproductive history variables with particular menstruation characteristics were found in the Caucasian and Japanese groups. For example, increased parity was associated with increased menstrual bleeding in both Caucasians and Japanese, and later age at menarche was significantly correlated with irregular menses in these two groups.