The relationships between periparturient serum levels of glucose urea, cholesterol, total protein, albumin, globulin, A/G ratio and subsequent fertility were studied in 15 pregnant buffalo-cows. Weekly blood samples were taken two weeks antepartum till eight weeks postpartum. A high significant (P<0.01) negative correlation between antepartum serum levels of urea, albumin, A/G ratio and postpartum fertility was found. After calving, a similar relationship was noticed between glucose, albumin and fertility. In buffalo - cows with significantly longer calving - conception interval (158.75 + 20.16 days), a high significant (P<0.01) decrease in urea and albumin concentrations before calving comparaed to a marked decrease of gluose, cholesterol and albumin levels after calving was found. Delayed onset of cyclicity till 210 days postpartum was associated with persistently lower levels of glucose, cholesterol, urea, albumin, globulin and A/G ratio around calving.