OBJECTIVES: Postmenopausal (PM) women taking hormone therapies (HT) can experience breast pain/tenderness and vaginal bleeding/spotting. To adequately assess those outcomes, the three-item Breast Pain and Tenderness Daily Diary (BPT-DD) and one-item Vaginal Bleeding and Spotting Daily Diary (VBS-DD) were developed to be administered electronically (eDiaries). The objective of the present study was to evaluate the psychometric properties of the newly-developed questionnaires using data from a prospective observational study. METHODS: The eDiaries were completed daily for 28 days by 202 PM women who experienced breast pain/tenderness and/or vaginal bleeding/spotting while on HT. Confirmatory factor analysis (CFA) was used to investigate the BPT-DD structure. Test–retest reliability (Intraclass Correlation Coefficient [ICC]), quality and distribution of responses, internal consistency (Cronbach’s alpha – for the BPT-DD only), convergent/discriminant validity and construct validity via known groups validity were assessed. RESULTS: Completion rates were high with over 90% of women missing no more than three daily entries over 28 days. BPT-DD inter-item correlations were adequate (r=0.77-0.89). CFA supported the unidimensional structure of the BPT-DD (Bentler’s Comparative Fit Index >0.98). BPT-DD internal consistency was satisfactory (Cronbach’s alpha= 0.95-0.97). A logical pattern of moderate correlations (>0.40) with scores from other instruments supported convergent/discriminant validity for both the BPT-DD and VBS-DD. The scales demonstrated good test–retest reliability (ICC ≥0.70) for responses averaged over one week.  Known groups analyses demonstrated that the VBS-DD and BPT-DD are able to significantly distinguish between groups of different severity (P<0.0001). CONCLUSIONS: These results provide evidence of strong psychometric properties for the BPT-DD and VBS-DD as assessments of breast pain/tenderness and bleeding in PM women.