Objective Although chemotherapy‐induced cognitive impairment is common among breast cancer patients, evidence for effective interventions addressing cognitive deficits is limited. This randomized controlled trial examined the feasibility and preliminary efficacy of a Tibetan Sound Meditation (TSM) program to improve cognitive function and quality of life in breast cancer patients. Methods Forty‐seven breast cancer patients (mean age 56.3 years), who were staged I–III at diagnosis, 6–60 months post‐chemotherapy, and reported cognitive impairment at study entry were recruited. Participants were randomized to either two weekly TSM sessions for 6 weeks or a wait list control group. Neuropsychological assessments were completed at baseline and 1 month post‐treatment. Self‐report measures of cognitive function (Functional Assessment of Cancer Therapy (FACT)‐Cog), quality of life (SF‐36), depressive symptoms (Center for Epidemiologic Studies Depression Scale), sleep disturbance (Pittsburgh Sleep Quality Index), fatigue (Brief Fatigue Inventory), and spirituality (FACT‐Sp) were completed at baseline, the end of treatment, and 1 month later. Results Relative to the control group, women in the TSM group performed better on the verbal memory test (Rey Auditory Verbal Learning Test trial 1) (p = 0.06) and the short‐term memory and processing speed task (Digit Symbol) (p = 0.09) and reported improved cognitive function (p = 0.06), cognitive abilities (p = 0.08), mental health (p = 0.04), and spirituality (p = 0.05) at the end of treatment but not 1 month later. Conclusions This randomized controlled trial revealed that TSM program appears to be a feasible and acceptable intervention and may be associated with short‐term improvements in objective and subjective cognitive function as well as mental health and spirituality in breast cancer patients. Copyright © 2013 John Wiley & Sons, Ltd.