Purpose Nonhormonal pharmacologic interventions are recommended for the treatment of hot flashes in breast cancer survivors. Antidepressants and gabapentin have been shown to be both effective and well tolerated; however, it is not clear which is preferred. Patients and Methods This was a group-sequential, open-label, randomized, cross-over trial of 4 weeks of venlafaxine (37.5 mg daily for 7 days followed by 75 mg daily for 21 days) versus gabapentin (300 mg once per day for 3 days, then 300 mg twice per day for 3 days, then 300 mg three times per day for 22 days), with patient preference as the primary outcome. Postmenopausal women with at least 14 bothersome hot flashes per week for the prior month were eligible. A 2-week baseline period and a 2-week tapering/washout time was used before the first and second treatment periods, respectively. Diaries were used to measure hot flashes and potential toxicities throughout the study. Participants completed a preference questionnaire at the end of the study. A predefined Pocock stopping rule was applied. Patient preference and hot flash and toxicity outcomes were compared between treatments. Results Sixty-six patients were randomly assigned, 56 of whom provided a preference (eight dropped out and two had no preference); 18 (32%) preferred gabapentin and 38 (68%) preferred venlafaxine (P = .01). Both agents reduced hot flash scores to a similar extent (66% reduction). Venlafaxine was associated with increased nausea, appetite loss, constipation, and reduced negative mood changes compared with gabapentin, whereas gabapentin was associated with increased dizziness and appetite compared with venlafaxine (all P < .05). Conclusion Breast cancer survivors prefer venlafaxine over gabapentin for treating hot flashes.