OBJECTIVES: To assess whether a specifically designed yoga intervention can reduce hyperkyphosis. DESIGN: A 6-month, two-group, randomized, controlled, single-masked trial. SETTING: Community research unit. PARTICIPANTS: One hundred eighteen women and men aged 60 and older with a kyphosis angle of 40 degrees or greater. Major exclusions were serious medical comorbidity, use of assistive device, inability to hear or see adequately for participation, and inability to pass a physical safety screen. INTERVENTION: The active treatment group attended hour-long yoga classes 3 days per week for 24 weeks. The control group attended a monthly luncheon and seminar and received mailings. MEASUREMENTS: Primary outcomes were change (baseline to 6 months) in Debrunner kyphometer-assessed kyphosis angle, standing height, timed chair stands, functional reach, and walking speed. Secondary outcomes were change in kyphosis index, flexicurve kyphosis angle, Rancho Bernardo Blocks posture assessment, and health-related quality of life (HRQOL). RESULTS: Compared with control participants, participants randomized to yoga experienced a 4.4% improvement in flexicurve kyphosis angle (P=.006) and a 5% improvement in kyphosis index (P=.004). The intervention did not result in statistically significant improvement in Debrunner kyphometer angle, measured physical performance, or self-assessed HRQOL (each P>.1). CONCLUSION: The decrease in flexicurve kyphosis angle in the yoga treatment group shows that hyperkyphosis is remediable, a critical first step in the pathway to treating or preventing this condition. Larger, more-definitive studies of yoga or other interventions for hyperkyphosis should be considered. Targeting individuals with more-malleable spines and using longitudinally precise measures of kyphosis could strengthen the treatment effect.