The results assessed from sugar beet microtrials at Kljaji evo (Serbia) in 2010 harvested at three harvest periods demonstrated that the average root yield tended to increase from the first to the third harvest period. The average increase in root yield between the first and the second harvest period was 29.06 t ha-1 or 32.76%, between the second and the third period 14.77 t ha-1 or 12.54% and between the first and the third period 43.83 t ha-1 or 49.40%. In average, the content of sugar in root showed a similar tendency. The highest increase in this parameter was registered between the second and the third harvest period and it amounted to 1.00% abs. Other indicators of sugar beet processing quality showed a slow increase or slight decrease depending on the harvest date, probably due to plentiful rainfall in September. Mean granulated sugar yield had an increasing tendency: 3.413 t ha-1 or 32.82% between the first and the second harvest period, 2.820 t ha-1 or 20.42% between the second and the third and 6.233 t ha-1 or 59.94% between the first and the third period.