The presence of the various categories of follicles (less than 0.05; 0.5-1.0; 1.0-1.5; less than 1.5 cm) in the ovaries was examined by palpation, endoscopically and post mortem in cows with a physiological puerperium (n = 5), with puerperal endometritis (n = 5), and with retention of afterbirth (RS, n = 5) from the second to the 20th day post partum (p.p.). The largest proportion (82.6%) of the smallest follicles (less than 0.5 cm) was recorded between the fourth and seventh day p.p. in clinically healthy cows; a marked decrease was then observed until the 15th day p.p. In cows with endometritis the proportion of the smallest follicles was only 60%. The average number of follicles 0.5 to 1.0 cm in size increased 1.6 times in the healthy cows between the 7th and 15th day p.p., but in cows with pathological puerperium their number declined. The largest follicles (greater than 1.5 cm) occurred in the cows with pathological puerperium as late as at the end of the period of study, whereas in healthy cows their occurrence was fairly frequent sooner--between the 8th and 11th day p.p. In all groups of cows the average number of follicles of all size groups declined until the 12th day p.p. which is an indication of the finished first growth wave. Occurrence of the first follicle larger than 1 cm in diameter was observed in 73.3% of cases in the contralateral ovary, opposite to the originally gravid uterine horn. It is assumed that delayed and asynchronous growth of follicles in cows with pathological puerperium is a consequence of disturbed repairing processes of endometrium and of endocrine dysfunction.