The mean Cu concentration in blood plasma of bulls of 12 Holstein and 13 Czech Spotted breeds was 22.27 µmol·l^-1; P, 1.78 mmol·l^-1; Ca, 3.04 mmol·l^-1; P:Ca ratio, 0.64. The mean Cu concentration in seminal plasma of bulls was 38.17 µmol·l^-1; P, 12.07 mmol·l^-1; and Ca, 3.52 mmol·l^-1 and the P:Ca ratio was 3.31. The relationship between Cu, P and Ca concentration in blood and seminal plasma is expressed by calculated phenotypic coefficients of correlation. Highly significant positive coefficients of correlation (P<0.01) were found between the Cu, P and P:Ca ratio in blood and seminal plasma (Cu - r_p=0.36, P - r_p=0.32 and P:Ca ratio r_p=0.28). In contrast, no positive relationship between the Ca concentration in blood plasma and seminal plasma was found; the calculated coefficient of correlation was negative (r_p =-0.16). This was probably caused by the higher Ca concentration in blood plasma of bulls. Statistically significant (P<0.05) positive coefficients of correlation were found between the Cu concentration in blood plasma and the total number of sperm in ejaculate (r_p=0.33), between the Cu concentration in blood plasma and the total number of sperm with progressive motility (r_p=0.35), and between the Ca concentration and monthly value of sperm motility (r_p=0.26). Positive coefficients of correlation were found between the Cu concentration in seminal plasma and the mean monthly volume of ejaculate (r_p=0.36, P<0.01), between the Cu concentration in seminal plasma and sperm motility (r_p=0.33, P<0.05), and Cu concentration in seminal plasma and total number of sperm with progressive motility in ejaculate (r_p=0.28, P<0.05). The P concentration in seminal plasma of bulls was positively correlated with the sperm concentration in ejaculate collected on test days (r_p=0.36, P<0.01). The correlation between the P:Ca ratio in seminal plasma and the sperm concentration in ejaculate collected on test days was positive (r_p=0.39, P<0.01) and so was the correlation between the P:Ca ratio and the mean monthly sperm concentration (r_p=0.28, P<0.05). The calculated coefficient of correlation between the Ca concentration in seminal plasma and the mean monthly sperm motility was negative (r_p=-0.38, P<0.01). It can be concluded that there is a positive relationship between the Cu and P concentrations and P:Ca ratio in seminal plasma of bulls and the quality and quantity parameters of ejaculate of active stud bulls. A higher concentration of Ca in seminal plasma negatively affected mainly sperm motility in this study.