OBJECTIVES: This study evaluated the qualitative equivalence between paper and electronic diary (eDiary) versions of 4 patient-reported outcome (PRO) instruments used in uterine fibroid studies: Menstrual Bleeding Scale, Uterine Fibroid Daily Symptom Scale, Non-Bleeding Uterine Fibroids Symptom (NBUFSQ) Questionnaire–Morning, and NBUFSQ–Evening.  Usability of study medication questions was also assessed. Equivalence evaluation of these questionnaires in an eDiary was needed to document suitability of this mode of data collection for upcoming clinical trials. METHODS: A cross-sectional qualitative study was conducted  at 2 US sites involving cognitive and usability interviews with premenopausal women diagnosed with uterine fibroids. The 4 symptom questionnaires and study medication questions were administered on HTC HD2 eDiary and paper versions. Participants were randomized to order of mode completion to control for order effects.  Interviews were conducted in two rounds to allow for evaluation of issues between rounds. RESULTS: Mean age of the sample (N=10) was 38 years, (range 25-48), 90% were white; 70% were employed full-time; 50% had completed secondary school or some college, while 50% had completed a college or postgraduate degree. All participants considered the formats similar. However, half the sample considered the layouts different. The majority preferred the eDiary to paper due to ease of use. Minor usability issues were noted in the numeric rating scale, with participants suggesting increasing the size or other modifications to make answer selection easier. Discrepancies in response between formats were found; 3 participants reported format differences may have affected their responses, while 5 participants said response differences were unrelated to the device.  No changes were made between rounds. CONCLUSIONS: The study showed excellent qualitative equivalence between paper and electronic versions of 4 PRO questionnaires.  This study also supported usability of the eDiary with a uterine fibroid population which preferred the eDiary and provided suggestions for improvement for future studies.