The chemical composition of a sample of fish meal was altered so that its contents of crude protein, metabolisable energy, methionine, lysine, calcium, phosphorus and salt equalled those of a sample of meat and bone meal. Choice-feeding balancer feeds were prepared in which various levels of the meat and bone meal were replaced by the fish meal mixture. Three samples of meat and bone meal were also compared. A balancer feed and whole wheat were offered ad libitum to broilers from three to seven weeks of age. Broiler performance and the proportion of whole wheat in the diet selected were similar for the three meat and bone meal samples. Birds fed on balancers containing increased levels of fish meal ate an increased proportion of whole wheat in their diet. Although balancers containing high levels of fish meal were the most expensive to produce, they gave the lowest total feed cost. A second experiment compared a meat and bone meal balancer, which was supplemented with either lysine, methionine, lysine plus methionine, a vitamin and mineral mix or a small amount of fish meal. None of the supplements markedly altered the feed intakes of whole wheat or balancer of the choice-fed broilers.