Abstract. The objective of this study was to examine the effect of season and transport time on beef quality. The study was conducted during 12 months of 2009 on 480 bulls and 480 heifers of Simmental breed. The cattle were divided into 2 transport groups and then into 4 season groups according to the journey. Quality indicators pH, electrical conductivity (EC) and meat colour values were measured 24 h post mortem on m. longissimus dorsi. Heifer beef compared to bull beef had better values of quality indicators (P<0.05). Differences in quality indicators were found between cattle slaughtered in the spring and summer seasons and between cattle slaughtered in the autumn and summer seasons (P<0.05). Bull beef had poorer colour, pH and EC values in the summer and winter seasons compared to the spring season, whereas heifer beef had poorer pH, EC and colour values in the summer period compared to other seasons (P<0.05). In the summer season, poorer pH, EC and colour (L* and h*) values were obtained in groups of heifers transported for a longer time compared to heifers transported for a shorter time (P<0.05). In groups of bulls transported for a shorter time during the winter period poorer pH, EC and colour values were obtained (P<0.05). This study suggests that the quality of Simmental beef was associated with the season and that environmental factors should be considered when deciding about the time of cattle transport, since this can reduce beef colour in a very short period of time.