The influence of the menstrual cycle on resting muscle sympathetic nerve activity (MSNA) remains controversial, and the effect of the menstrual cycle on MSNA responses to mental stress is unknown. We examined MSNA, mean arterial pressure (MAP), and heart rate (HR) responses to mental stress (via mental arithmetic) in 11 healthy females during the early follicular (EF) and mid-luteal (ML) phases of the menstrual cycle. The menstrual cycle did not alter resting MSNA (EF, 13±3 bursts/min vs. ML, 13±2 bursts/min), MAP (EF, 79±3 mmHg vs. ML, 81±2 mmHg) and HR (EF, 66±3 beats/min vs. ML, 64±2 beats/min). Five minutes of mental stress increased MSNA, MAP, and HR during both the EF (4±2 bursts/min, 12±2 mmHg, 18±2 beats/min; P<0.05) and ML (4±2 bursts/min, 13±3 mmHg and 20±2 beats/min; P<0.05) phases. These responses were not different between phases. In contrast, MSNA responses were different between phases during the 10 min recovery from mental stress. MSNA remained elevated during the initial five minutes of recovery in both the EF (6±1 bursts/min; P<0.01) and ML (7±1 bursts/min; P<0.01) phases, but only remained elevated during the ML phase (6±1 bursts/min; P<0.01) during the final five minutes of recovery. Our results demonstrate that MSNA, MAP, and HR responses at rest or during mental stress are not different during the EF and ML phases of the menstrual cycle in young, healthy females. However, MSNA activation during recovery from mental stress appears to be prolonged during the ML phase compared to the EF phase.