For millions of breast cancer survivors (BCS) and menopausal women without breast cancer (MW), hot flashes are frequent, severe, and bothersome events that can interfere with daily life and negatively influence mood, affect, and/or sleep. Unfortunately, the scientific basis for managing hot flashes is limited. The major conclusion from a recent National Institutes of Health state-of-the-science conference was that additional data are needed on the efficacy and appropriateness of non-hormonal hot flash treatments. Although slow deep breathing has been recommended by the North American menopause Society as a first-line treatment for hot flashes, these recommendations are based on two previous studies that included small numbers of MW, used complex time- and resource-intensive instructional protocol, and incorporated a narrow range of outcomes. These limitations restrict current evidence for efficacy and reduce the likelihood that this promising non-hormonal hot flash treatment can be disseminated into widespread use. The proposed randomized, controlled trial evaluates a simplified DVD-based at-home breathing training and practice program against an attention control and a no-treatment usual care control condition among BCS and MW without breast cancer. Aims are to evaluate (1) efficacy for physiologic and subjective hot flashes (objective frequency and subjective frequency, severity, bother, and duration), (2) efficacy for perceived hot flash interference and associated outcomes (mood, affect, sleep), (3) differences in efficacy between BCS and MW without cancer, and (4) acceptability, outcome expectancy, treatment credibility, and frequency of practice and application. This study will also examine baseline characteristics as potential covariates of efficacy, including objective hot flash frequency, body mass index, race, ethnicity, education prior breath training, smoking status, menopausal status, use of selective estrogen receptor modulators or aromatase inhibitors, use of other hot flash treatments, and comorbid conditions. A total of 91 BCS and 91 MW will be stratified and randomized using a 2:2:1 ratio to intervention, attention control, or usual care groups. Outcomes will be assessed at baseline, 8 and 16 weeks post-intervention by research assistants masked to randomization group. A portable respiratory transducer will be used to evaluate breathing depth and rate. Findings will provide empirical evidence for or against the use of slow deep breathing for relieving physiologic and/or subjective hot flashes, perceived hot flash interference and associated outcomes. Positive or negative findings will guide clinicians' recommendations and consumers' treatment selections either in favor of, or against, the use of slow deep breathing. If efficacious, acceptable, and usable, this DVD-based program could be easily and widely disseminated for use in lieu of, or in addition to, currently available hot flash treatments.