OBJECTIVES: Cancer survivors often report cognitive problems. Furthermore, decreases in physical activity typically occur over the course of cancer treatment. Although physical activity benefits cognitive function in noncancer populations, evidence linking physical activity to cognitive function in cancer survivors is limited. In our recent randomized controlled trial, breast cancer survivors who received a yoga intervention had lower fatigue and inflammation following the trial compared with a wait list control group. This secondary analysis of the parent trial addressed yoga's impact on cognitive complaints. METHODS: Posttreatment stage 0-IIIA breast cancer survivors (n = 200) were randomized to a 12-week, twice-weekly Hatha yoga intervention or a wait list control group. Participants reported cognitive complaints using the Breast Cancer Prevention Trial Cognitive Problems Scale at baseline, immediately postintervention, and 3-month follow-up. RESULTS: Cognitive complaints did not differ significantly between groups immediately postintervention (p = 0.250). However, at 3-month follow-up, yoga participants' Breast Cancer Prevention Trial Cognitive Problems Scale scores were an average of 23% lower than wait list participants' scores (p = 0.003). These group differences in cognitive complaints remained after controlling for psychological distress, fatigue, and sleep quality. Consistent with the primary results, those who practiced yoga more frequently reported significantly fewer cognitive problems at 3-month follow-up than those who practiced less frequently (p < 0.001). CONCLUSIONS: These findings suggest that yoga can effectively reduce breast cancer survivors' cognitive complaints and prompt further research on mind-body and physical activity interventions for improving cancer-related cognitive problems.