The objectives of the present study were to compare the growth curve models for their ability to describe the growth of Turkish Norduz sheep, and to estimate the growth curve parameters by the selected growth model. The data were collected from 93 male lambs and 86 female lambs from birth to 198 day of age. Five different nonlinear models, Brody, Gompertz, Logistic, Bertalanffy and Negative exponential, were compared using coefficient of determination (R-2), asymptotic mature weight (BWA), residual standard deviation (RSD) and coefficient of correlation (r) between the observed and estimated growth curves. The Logistic growth model was observed to be appropriate for explaining the growth of Norduz female and male lambs. Male lambs grew faster and attained larger mature weight than female lambs showing that sex is the main factor affecting the growth of Norduz lambs. Type of birth had no effect on the growth of the lambs.