The study aimed at verifying the effect of soccer refereeing on power performances, evaluated by means of countermovement (CMJ) and bounce (BJ) jumps. Ten soccer referees (age 23 +/- 3 years; V(.-)O2max 51.8 +/- 3.2 ml x kg(-1) x min(-1)) participated in this study. The physical load of refereeing was evaluated by means of subject's heart rate (HR), motor activities recorded during the match, and blood lactate measured at the end of the 2 halves. Analysis of variance and chi-square tested the differences between halves (p < 0.05). During the first half, the occurrence of subject's HR >85%HRmax was 62 +/- 31%, and it significantly (p < 0.05) decreased to 45 +/- 24% during the second half. Referees spent 41 +/- 5% running, 44 +/- 6% walking, and 15 +/- 5% inactivity, with no significant differences between halves. Blood lactate was significantly different only between warm-up (2.0 +/- 0.4 mM) and first half (4.7 +/- 2.9 mM). No significant difference emerged for CMJ and BJ after the 2 halves, demonstrating that young referees with acceptable fitness levels are able to maintain their all-out capabilities during the whole match.