The efficacy of meloxicam in the treatment of sows with mastitis–metritis–agalactia syndrome was investigated in comparison with flunixin. Basic therapy comprised administration of an antibiotic and oxytocin. A total of 200 sows and litters were examined in a double-blind clinical study with observations up to 8 days after the first treatment. The primary parameter, the clinical index score on day 2, consisting of rectal temperature, feed intake, general demeanour, respiratory rate, vaginal discharge, degree of inflammation of mammary glands, milk flow and nursing behaviour, revealed a significant (P ≤ 0.05) non-inferiority of meloxicam in comparison with flunixin implying equal efficacy of both drugs. No significant differences were noted in the distribution of clinical efficacy scores within both groups at each day of examination. The differences in litter weight and daily weight gain per piglet were not significant between the two test groups. The mortality rates until day 8 of the study were without significant difference between groups. In piglets of diseased litters, however, the mortality rate was 50% lower in the meloxicam group in comparison with the reference group, this difference reaching statistical significance (P ≤ 0.05).