This study compared acute (15 min) yoga posture and guided meditation practice, performed seated in a typical office workspace, on physiological and psychological markers of stress. Twenty participants (39.6 ± 9.5 yr) completed three conditions: yoga, meditation, and control (i.e., usual work) separated by ≥24 hrs. Yoga and meditation significantly reduced perceived stress versus control, and this effect was maintained postintervention. Yoga increased heart rate while meditation reduced heart rate versus control (P < 0.05). Respiration rate was reduced during yoga and meditation versus control (P < 0.05). Domains of heart rate variability (e.g., SDNN and Total Power) were significantly reduced during control versus yoga and meditation. Systolic and diastolic blood pressure were reduced secondary to meditation versus control only (P < 0.05). Physiological adaptations generally regressed toward baseline postintervention. In conclusion, yoga postures or meditation performed in the office can acutely improve several physiological and psychological markers of stress. These effects may be at least partially mediated by reduced respiration rate.