OBJECTIVE: This study aims to assess the agreement between the menopausal transition stages defined by annual interviews or annual follicle-stimulating hormone levels and the menopausal transition stages defined by monthly menstrual calendars, as well as factors associated with discordance. METHODS: These analyses used daily self-recorded menstrual calendar data from 1996 to 2006, annual interviews, and annual follicle-stimulating hormone levels. Participants were recruited from four study sites of the Study of Women's Health Across the Nation (Boston, southeastern Michigan, Oakland, and Los Angeles) and four racial/ethnic groups (African American, white, Chinese, and Japanese). Women who had a defined final menstrual period and who never had hormone therapy were included (n = 379). Cohen's kappa statistics for 2 x 2 tables were calculated for two definitions of agreement. Logistic regression was used to identify factors associated with discordance. RESULTS: Poor agreement between annual interview and menstrual calendar data was found for early menopausal transition (kappa = -0.13; 95% CI, -0.25 to -0.02) and late menopausal transition (kappa = -0.18; 95% CI, -0.26 to -0.11). For late stage, Chinese women (odds ratio [OR], 2.16; 95% CI, 1.08 to 4.30), African-American women (OR, 2.39; 95% CI, 1.00 to 5.71), and women with high school education or less (OR, 2.16; 95% CI, 1.08 to 4.30) were more likely to be discordant. Poor agreement between annual follicle-stimulating hormone levels and menstrual calendars was also found for early menopausal transition (kappa = -0.44; 95% CI, -0.57 to -0.30) and late menopausal transition (kappa = -0.32; 95% CI, -0.42 to -0.23). CONCLUSIONS: New questions need to be developed to accurately identify the start of the menopausal transition and should be evaluated in a multiethnic population with varying educational backgrounds.