To assess the feasibility, safety, and initial estimates of efficacy of a yoga program in postoperative care for women at high risk for breast cancer-related lymphedema (BCRL).Single-group pretest-post-test design.Patients were recruited from the University of California, San Francisco Carol Franc Buck Breast Care Center.Twenty-one women were enrolled in the study. Women were >18 years of age, had undergone surgical treatment for breast cancer, and were at high risk for BCRL.The women participated in an Ashtanga yoga intervention for 8 weeks. Sessions consisted of once/week instructor-led practice and once/week home practice. Particular attention was given to poses that emphasized upper body strength and flexibility, while avoiding significant time with the upper extremity (UE) in a dependent position.UE volume was assessed through circumferential forearm measurement, which was converted to volume using the formula for a truncated cone. Range of motion (ROM) was assessed for the shoulders, elbows, and wrists, using a standard goniometer. UE strength was assessed for shoulder abduction, elbow flexion, wrist flexion, and grip using a dynamometer.Twenty women completed the yoga intervention, with 17 returning for final assessment. Mean age was 52 (±9.1) years and body mass index was 24.8 (±5.1) kg/m2. Postintervention, mean volume in the at-risk UE was slightly reduced (p = 0.397). ROM for shoulder flexion (p < 0.01) and external rotation (p < 0.05) significantly increased bilaterally. Shoulder abduction ROM significantly improved for the unaffected limb (p = 0.001). Following intervention, strength improved on the affected side for shoulder abduction and grip strength, and bilaterally for elbow flexion (p < 0.05 for all).These preliminary findings suggest that yoga is feasible and safe for women who are at risk for BCRL and may result in small improvements in shoulder ROM and UE strength.