Twenty ostrich chicks (Struthio camelus) up to 8 weeks of age were fed isocaloric diets containing protein levels of 14%, 16%, 18% and 20%. The highest mean body weight gain was obtained from feeding the 20% protein diet; however, this result was not significantly different at the 0.05 level of probability. Feed conversion favoured the 18% protein group. During the seventh and eighth week of the experimental period some chicks developed leg deformities. Clinical signs, radiological findings and response to calcium supplementation suggested an insufficient amount of calcium in the experimental diets.