The performance and gut measurements of broilers fed on diets containing different amounts of chaya (Cnidoscolus aconitifolius) leaf meal (CLM) were examined in two experiments. In the first experiment, 60 Hubbard chickens (30 males and 30 females; 2 weeks old) were fed on five maize diets; these were formulated using 0, 150 (CLM150), 250 (CLM250) or 350 (CLM350) g CLM/kg, and the fifth diet contained soyabean. In the second experiment, 148 Ross male chicks, 1 day old, were fed on three isonitrogenous and isoenergetic maize–soyabean-based diets, which included 0 (control), 150 (C150) or 250 (C250) g CLM/kg. The diets were offered ad libitum for 2 or 3 weeks in the first and second experiments, respectively. Food intake, weight gain and the food:weight gain ratio were recorded. The weight of the gizzard and intestine and the weight and length of the caeca were also determined in the second experiment. In experiment 1, the birds fed on the maize–soyabean diet had a higher (p<0.05) weight="" gain="" and="" final="" weight="" than="" birds="" fed="" on="" maize="" only="" or="" on="" the="" clm150="" diets.="" there="" were="" no="" differences="" for="" any="" of="" the="" variables="" studied="" between="" the="" birds="" fed="" on="" the="" maize–soyabean="" diet="" and="" those="" fed="" on="" the="" clm250,="" nor="" between="" males="" and="" females.="" in="" the="" second="" experiment,="" weight="" gain,="" food="" intake="" and="" the="" food:weight="" gain="" ratio="" for="" birds="" fed="" on="" c250="" were="" lower="">p<0.05) than="" those="" in="" birds="" fed="" on="" either="" the="" control="" or="" c150="" diets.="" the="" weights="" of="" the="" gizzard="" and="" intestine="" were="" the="" lowest="" and="" the="" highest,="" respectively,="" in="" birds="" fed="" on="" c250="">p<0.05). the="" length="" and="" weight="" of="" the="" caecum="" from="" birds="" fed="" on="" the="" control="" diet="" were="" lower="">p<0.05) than="" those="" of="" birds="" fed="" on="" either="" the="" c150="" or="" c250="" diets.="" the="" results="" from="" this="" study="" suggest="" that="" clm="" may="" be="" included="" up="" to="" 150="" g/kg="" in="" commercial="" diets="" without="" having="" an="" adverse="" effect="" on="" poultry="" performance,="" and="" may="" also="" be="" mixed="" with="" maize="" up="" to="" 250="" g/kg="" to="" improve="" the="" performance="" of="" chickens="" fed="" on="" low-protein="">