We examined whether spontaneous baroreflex modulation of heart rate and other indices of cardiac vagal tone could be altered by passive stretch of the human calf muscle during graded concurrent activation of the muscle metaboreflex. 10 healthy subjects performed 4 trials, a control trial, resting for 1.5mins (0% trial), or performed 1.5mins of one-legged isometric plantarflexor exercise at 30, 50 and 70% maximal voluntary contraction. The incremental increases in blood pressure (BP) caused were then partially sustained by subsequent local circulatory occlusion (CO). After 3.5mins of CO alone sustained calf stretch and CO was applied for 3min. Spontaneous baroreflex sensitivity (SBRS) was progressively decreased with increasing exercise intensity (P<0.05 During CO stretch decreased SBRS and increased BP similarly in all trials (P<0.05). Within 15s of stretch onset , HR increased by 6 ± 1, 6 ± 1, 8 ± 1 and 6 ± 2 b.min^-1 in the 0, 30, 50 and 70% trials, respectively (P<0.05), and root mean square of successive differences was decreased from CO-alone levels (P<0.05). During the second and third minutes of stretch, HR fell back but remained significantly above CO levels, and common coefficient of variance of R-R interval decreased progressively with increasing prior exercise intensity (P< 0.05, 70% trial). This suggests that passive stretch of the human calf muscles decreases cardiac vagal outflow irrespective of the levels of BP increase caused by muscle metaboreflex activation and implies that central modulation of baroreceptor input, mediated by the actions of stretch activated mechanoreceptive muscle afferent fibres, continues.