1. Growing turkeys were kept at one of 4 constant temper- atures (14, 17, 20 or 23 C) from 10 to 15 weeks of age and given a food with one of three protein concentrations (201, 229 or 294 g/kg diet). 2. Food intakes, food conversion ratios and breast meat yields (as a proportion of body weight) were decreased at the higher temperatures but there were no significant differences in growth. 3. At each temperature, the turkeys given the higher dietary protein concentrations had increased body weight gains but their breast meat yields were similar. Thus the poor breast meat yields which resulted from rearing at high temperatures could not be counteracted by high dietary protein concentrations.