Abstract: Supplementation of organic trace minerals is gaining importance in broiler chickens due to higher mineral bioavailability. Among the trace minerals, zinc (Zn) and manganese (Mn) are of particular interest, because they are associated with growth, skeletal soundness and immune response. Therefore, organic Zn (40, 80 or 160 ppm) and Mn (60, 120 or 240 ppm) at variable levels were tested in a factorial pattern to examine the level effects and their interactions on broiler growth, bone morphometry, mineral tissue uptake and immune response at 35 days of age. A total of 486 commercial Cobb broiler chicks was equally distributed to 9 dietary groups with 9 replicates of 6 birds each in stainless-steel battery brooders. Feed and water were offered ad libitum to all chicks. The results indicated that body weight gain, feed conversion efficiency, leg scores, tibia weight and tibia strength were not influenced by the supplemental levels of Zn and Mn and their interactions at 35 days of age. Bone mineralization and accumulation of Zn and Mn in tibia were significantly (p≤0.05) higher with Zn supplementation in diets at 80 ppm level, while, the Mn deposition was enhanced linearly (10.47-16.36 ppm) with progressive increase of Mn level in diets. However, Mn at 60 ppm complimented Zn retention significantly (p≤0.01). The interaction between Zn and Mn at 80 and 60 ppm, respectively supported their retention (p≤0.01) in hepatic tissue. The humoral immune response was significantly (p≤0.05) higher with Zn and Mn at 80 and 60 ppm levels, respectively. In conclusion, the results suggest that the combination of organic Zn and Mn at 80:60 ppm was synergistic for enhanced bone mineralization, mineral uptake by tissues and immune response, though the growth performance and bone morphmetry remained unchanged due to variable Zn and Mn levels and their combinations in broiler chicken at 35 days of age.