In dairy farm animals, production of milk and its components varies in a curvilinear pattern over the course of the lactation. Knowledge of the lactation curve may provide a worthwhile information source about the pattern of milk production which in turn could be used for herd management decisions. Moreover, inter-relationships among lactation curve parameters could be utilised in applied animal breeding programmes to change more effectively the shape of the lactation. Many studies have been undertaken to apply different mathematical models to obtain more accurate prediction of the shape of the lactation curve among which the incomplete gamma function first proposed by Wood (1967) has been broadly used by previous research workers (Rekaya et al., 2000; Tekerli et al., 2000). The main objective of the present research was to apply Wood’s function for estimating phenotypic correlations among lactation curve parameters in Iranian first lactation buffaloes.