BACKGROUND: Hot flushes and night sweats (HFNS) - the main symptoms of the menopause transition - can reduce quality of life and are particularly difficult to manage at work. A cognitive behaviour therapy (CBT) intervention has been developed specifically for HFNS that is theoretically based and shown to reduce significantly the impact of HFNS in several randomised controlled trials (RCTs). Self-help CBT has been found to be as effective as group CBT for these symptoms, but these interventions are not widely available in the workplace. This paper describes the protocol of an RCT aiming to assess the efficacy of CBT for menopausal symptoms implemented in the workplace, with a nested qualitative study to examine acceptability and feasibility. METHODS/DESIGN: One hundred menopausal working women, aged 45-60 years, experiencing bothersome HFNS for two months will be recruited from several (2-10) large organisations into a multicentre randomised controlled trial. Women will be randomly assigned to either treatment (a self-help CBT intervention lasting 4 weeks) or to a no treatment-wait control condition (NTWC), following a screening interview, consent, and completion of a baseline questionnaire. All participants will complete follow-up questionnaires at 6 weeks and 20 weeks post-randomisation. The primary outcome is the rating of HFNS; secondary measures include HFNS frequency, mood, quality of life, attitudes to menopause, HFNS beliefs and behaviours, work absence and presenteeism, job satisfaction, job stress, job performance, disclosure to managers and turnover intention. Adherence, acceptability and feasibility will be assessed at 20 weeks post-randomisation in questionnaires and qualitative interviews. Upon trial completion, the control group will also be offered the intervention. DISCUSSION: This is the first randomised controlled trial of a self-management intervention tailored for working women who have troublesome menopausal symptoms. TRIAL REGISTRATION: Clin.Gov NCT02623374.