Endurance exercise training increases smooth muscle L-type Ca²⁺ current density in both resistance and proximal coronary arteries of female miniature swine. The purpose of the present study was to determine 1) whether gender differences exist in coronary smooth muscle (CSM) L-type Ca²⁺ current density and 2) whether endurance training in males would demonstrate a similar adaptive response as females. Proximal, conduit (~1.0 mm), and resistance [~200 µm (internal diameter)] coronary arteries were obtained from sedentary and treadmill-trained swine of both sexes. CSM were isolated by enzymatic digestion (collagenase plus elastase), and voltage-gated Ca²⁺-channel current (I_Ca) was determined by using whole cell voltage clamp during superfusion with 75 mM tetraethylammonium chloride and 10 mM BaCl₂. Current-voltage relationships were obtained at test potentials from 60 to 70 mV from a holding potential of 80 mV, and I_Ca was normalized to cell capacitance (pA/pF). Endurance treadmill training resulted in similar increases in heart weight-to-body weight ratio, endurance time, and skeletal muscle citrate synthase activity in male and female swine. I_Ca density was significantly greater in males compared with females in both conduit (7.57 ± 0.58 vs. 4.14 ± 0.47 pA/pF) and resistance arteries (11.25 ± 0.74 vs. 6.49 ± 0.87 pA/pF, respectively). In addition, voltage-dependent activation of I_Ca in resistance arteries was shifted to more negative membrane potentials in males. Exercise training significantly increased I_Ca density in both conduit and resistance arteries in females (7.01 ± 0.47 and 9.73 ± 1.13 pA/pF, respectively) but had no effect in males (8.61 ± 0.50 and 12.04 ± 1.07 pA/pF, respectively). Thus gender plays a significant role in determining both the magnitude and voltage dependence of I_Ca in CSM and the adaptive response of I_Ca to endurance training.