Abstract: The use of boiled pigeon seeds as a replacement for groundnut cake in the diets of broiler chickens was evaluated in growth performance, carcass and haematological studies. Five each of broiler starter and finisher diets were formulated to contain, 0, 20, 40, 60, 80 and 0, 25, 50, 75, 100% of pigeon pea meal protein as replacement for soyabean meal protein, respectively. One hundred and twenty (120), 1 week old broilers were divided into five groups of 24 birds each and were randomly assigned to the five dietary treatments in a Completely Randomised Design (CRD). Each group had 3 replicates of chicks each. Water and feeds were offered Ad libitum. The results obtained indicated that pigeon pea meal protein replacement for soyabean meal protein up to 50% level in the finisher diet supported growth or total weight gain without any significant (p<0.05) depression. Total weight gain deceased significantly (p<0.05) with higher levels of pigeon pea meal protein replacement for soyabean meal. Feed utilization viz., feed intake, feed efficiency and protein efficiency ratios were not significantly (p>0.05) affected by dietary treatments. Carcass and organ weights decreased significantly (p<0.05) with increasing levels of pigeon pea meal in the diets. Haematological values were also significantly (p<0.05) affected. Haemoglobin, white blood cells, packed cell volume, leutrophils and the differential white blood cell counts were observed higher among chickens fed control diets and generally decreased with increasing levels of pigeon pea meal in the diets. Total serum protein, albumin and globulin value recorded among the chickens fed control diets can be considered low when compared with values obtained for the test diets. It is important to add that the negative effects of decrease or increase in some blood parameters had no observed serious negative impact on chickens fed diets 2 and 3 containing up to 50% pigeon pea meal protein replacement for soyabean meal protein since they were not inferior to chickens fed the control diet with regard to growth performance.