OBJECTIVE: The purpose was to explore cyclicity of breast tenderness and vasomotor symptoms in menstruating mid-life women using the Daily Perimenopause Diary. METHODS: Untreated mid-life women from a convenience sample completed the Daily Perimenopause Diary for clinical (n = 14) or research (n = 10) assessments. Breast tenderness, sleep disturbance and day and night vasomotor intensity were rated on a 0-4 scale with vasomotor number as a count. Daily oral temperature data were analyzed using the Quantitative Basal Temperature algorithm to assess ovulation and estimate luteal phase length. Analysis of variance tested cyclicity using the mean of three 3-day windows (during flow, at mid-cycle and premenstrually). RESULTS: Ninety-eight complete flow-to-flow diaries (from 24 women, mean age 47 years, cycle length 27 +/- 6.4 (standard deviation) days) were available, with quantitative temperature data for 60 cycles in 16 women. Of assessed cycles, 90% were ovulatory; 25% had luteal phases < 10 days. Breast tenderness was maximal in the premenstrual window overall (p