The growth of 29 Black-browed and 46 Grey-headed Albatross chicks was studied for 95 d after hatching at Bird Island, South Georgia. A family of sigmoid curves was explored to find suitable forms for describing the growth of these species and the parameters were estimated and compared by appropriate statistical techniques. The growth curves of both species were of the same form although Black-browed Albatross chicks grew faster and attained a higher maximum weight than Grey-headed Albatross chicks. The rate of development of the wings in both species was related to increase in weight but the relationship was different in each species. These differences in growth, together with dietary differences, may influence the breeding pattern of these two species.