The records of 457 Surti buffaloes with 1346 lactations sired by 35 sires maintained at Livestock Research Station, Navsari Agricultural University, Navsari born during 1987 to 2012 were collected and analysed to examine the effect of non-genetic factors viz. season and period of birth on age at first calving. The average age at first calving in Surti buffaloes was found to be 1333.96 ± 19.53 days. The analysis of variance revealed highly significant effect of period of birth but non-significant effect of season of birth on age at first calving. No effect of season of birth on age at first calving indicated breed characteristics to acclimatize with environment. Age at first calving showed a significant rise during Period-2 (1993 to 1998) and Period-3 (1999 to 2004) and subsequent decline in Period-4 (2004-2012) indicates improvement of managemental practices over the periods of the farm.