The economy of Ca utilization is under the control of vitamin D3, particularly its active metabolite 1,25-dihydroxy cholecalciferol [1,25(OH)2D3]. In sufficient Ca absorption leads to tibial dyschondroplasia resulting in not attaining optimum body weight. Our earlier studies [T.P. Prema, N. Raghuramulu, Phytochemistry 37 (1994) 167] have shown that the Cestrum diurnum (CD) leaves contain vitamin D3 metabolites. It was felt whether incorporation of CD as a source of 1,25(OH)2D3 could improve the Ca absorption in broilers. Four groups of 60 birds each were fed with either normal diet or normal diet+0.25% CD or normal diet without vitamin D3 or normal diet without vitamin D3 +0.25% CD leaf powder for 45 days. In subsample of six birds it was observed that incorporation of CD leaves in the feed had the maximal effect on all the parameters studied. The results indicate that the intestinal Ca transport as represented by Serosa/Mucosa (S/M) ratio was found to be significantly (p <0.01) higher in broilers fed diet with CD leaf powder and the 1α hydroxylase activity in kidney is significantly (p <0.001) higher in negative controls. On the other hand the supplementation of CD leaves enhanced the serum Ca, body weight, tibia weight, density and strength resulting in the disappearance of tibial dyschondroplasia. No lesions of toxicity were observed in any of the soft tissue examined. The results suggest that the incorporation of CD leaf powder in poultry feed could be beneficial to the poultry.