The main object of this research was to determine the existance of statistically significant differences in physiological load of the referees concidering the period of the basketball game. The sample of subjects consisted of 31 referees, avarage age of 33.35 ± 5.17, from the A referee list of the 1st Croatian Basketball League in the contest season 2008/2009. The sample of variables consisted of the following: FSM - avarage heart rate; Fsmax – maximum heart rate; E – energy consumption (kcal/min). Measuring was done during official games of the 1st Croatian Basketball League in the contest season of 2008/2009. During the game, heart rate was measured with a cardiotachometer (an electronic device for heart rate measurement), produced by POLAR, model RS400 (Finland). Data processing was done using a programme package STATISTICA for Windows, ver 8. Based on the obtained results of univariate variance analysis it was concluded that there are no statistically significant differences in the physiological load between the first and second half – time, as well as between particular quarters of basketball games.