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 of birth, period of birth and parity on lactation length. The average calving interval in Surti buffaloes was found to be 447.92 ± 9.52 days. The analysis of variance revealed highly significant effect of parity but non-significant effect of period of birth and season of birth on calving interval. No effect of period of birth and season of birth on calving interval indicated breed characteristics to acclimatize with environment and managemental practice. Calving interval showed a significant decline from Parity-2 to Parity-8 indicates good reproductive management in farm.