A total of 32 cows equal in terms of breed, annual milk productivity, feeding and tending regime were examined to determine the clearance of the uterine microflora during the puerperal period and establish the correlation between the conception rate and the bacterial clearance. The studies were carried out on the day of calving and on the 3rd, 6th, 9th, 12th and 15th day after that. It was found that in cows manifesting certain troubles during the puerperal period the bacterial count in the uterine discharges was 75.3% higher as early as the very first day following calving, and regardless of the drop after the ninth day, by the fifteenth day it was 64 per cent higher than in animals showing normal puerperium. In 40.8 per cent of the cows the discharge afterbirth on the day of calving showed no microorganisms. The rise of the microbial count was noted after the first day. It reached its maximum values by the 9 - 10th day after calving, after which it showed a dropping trend. The conception rate of cows with a normal puerperium at first service was 58.1 percent.