OBJECTIVES: To examine whether long-term practice of yogic breathing alters cardiac autonomic control. DESIGN: Age-sex matched, cross-sectional, physiologic pilot study. SETTINGS/LOCATION: Spaulding Rehabilitation Hospital, Cardiovascular Laboratory, Cambridge, MA. PARTICIPANTS: Twenty-six (26) long-term yoga practitioners and 26 age- and sex-matched controls, free of cardiovascular disease. OUTCOME: Cardiac vagal outflow as assessed by respiratory sinus arrhythmia (RSA). RESULTS: During unpaced (spontaneous) breathing, yoga practitioners exhibited augmented RSA compared to controls (yoga 364.8 ± 75.3 vs. 194.7 ± 46.0 msHz, p = 0.03). However, during paced breathing at 0.25 Hz (15 breaths/min), which accounts for inter- and intravariability in breath rate, RSA did not differ between groups (yoga 224.8 ± 48.4 vs. 271.3 ± 59.7 msHz, p = 0.98). Furthermore, the relationship between age and RSA, such that RSA declines with age, did not qualitatively differ between groups. CONCLUSIONS: Long-term practice of yogic slow breathing does not appear to augment cardiac vagal control nor prevent known age-related declines.