In the supine resting condition, muscle sympathetic nerve activity (MSNA) is higher in men than women. Furthermore, cardiac output is related to MSNA in young men, but not in young women. Increased pulsatile sinus pressure evokes sustained reductions in sympathetic activity (Chapleau, et al., 1989) and depressor response (Mendelowitz and Scher, 1988). Thus, carotid-pressure interactions may partially explain within and between sex differences in neural outflow to skeletal muscle. To begin to assess this question, six young men and four young females were studied in the resting supine condition. Muscle sympathetic nerve activity and heart rate (ECG) were obtained continuously during 6 minutes of spontaneous breathing. Blood pressure was obtained in duplicate by electrosphygmomanometry. Simultaneously, carotid sinus pulsatility was measured continuously for the first minute using high-resolution ultrasonography. Beat-by-beat systolic and diastolic sinus diameters were obtained using wall tracking software and averaged. Carotid tensile force during diastole was calculated as the product of diastolic blood pressure and diastolic cartid radius and expressed as diastolic static wall tension (SWTdia, mmHg x mm). Pulsatile wall tension (PWT) was calculated as PWT (mmHg·mm) = (pressure x radius)systole – (pressure x radius)diastole. These data are preliminary, thus data are expressed as mean differences and effect sizes (ES). Muscle sympathetic nerve activity (Δ19, beats·100 hb−1, ES 4.6), mean arterial pressure (Δ7, mmHg, ES 1.20) and SWTdia (Δ4, mmHg·mm, ES 1.8, Figure) seemed greater in men than women. Average pulse pressure (Δ0.5, mmHg, ES <0.1) alongside PWT (Δ1, mmHg, ES 0.2) seemed similar between sexes. These observations were similar when hemodynamics was scaled to height. No relationship was observed between SWTdia and muscle sympathetic nerve activity in men or women (R<0.1). In young men, PWT was negatively related to muscle sympathetic nerve activity (R2=0.63, Figure) whereas in young women the relationship was positive but very weak (R2=0.27, Figure). These preliminary data suggest that carotid-pressure pulsatility, even in the resting sate, is related to basal sympathetic outflow in young males. In young females, carotid-pressure interactions seem to play a smaller role.