The reproductive performance of cows with post parturient metritis treated systemically with long-acting oxytetracycline was compared with normal herd mates in four South African dairy herds. The incidence of metritis for all calvings in these herds was 7.5% (of 1838 calvings), 3.6% (of 715 calvings), 4.6% (of 455 calvings) and 2.8% (of 357 calvings), respectively. The comparative median days to first insemination and conception between normal and metritic cases in the largest herd were 75 versus 85 and 92 versus 140, respectively. On average, more inseminations per conception (2.06) were needed for metritic cases when compared with normal herd mates (1.52) in this herd. These differences were statistically significant (P < 0.01). No significant differences in these parameters were apparent between metritic cases and normal herd mates in the other three herds.