This study was conducted to estimate the effect of Piliostigma thonningii leaf (PTLM) and pod (PTPM) meals on growth performance, nutrient digestibility, nitrogen balance, rumen metabolites, methane emission and the economic benefit of including PTLM and PTPM in diet of Yankasa lamb rams. A total of eight lamb rams weighing 18 to 23kg on average were randomly assigned to four dietary treatments containing PTLM and PTPM of 13.91 and 13.59% crude protein in a complete diet. The diets containing 0, 5, 10 and 15% inclusion levels of PTLM and PTPM were fed to the lamb rams at 4% of their body weights in a trial period that lasted 90days for both PTLM and PTPM in a 4×4 Latin Square Design. Results obtained showed that the average values for weight gain, average weight gain and feed conversion ratio respectively were significantly (P<0.05) affected by inclusion levels of PTLM and PTPM. Lamb rams fed 5% inclusion of PTLM had corresponding values of 2.37kg, 169.64g/day and 5.79 compared to PTPM which had 2.63kg, 187.50g/day and 7.50. The crude fibre, ether extract and nitrogen free extract digestibility in Yankasa lamb rams were significantly (P<0.05) affected by varying inclusion levels of PTLM and PTPM. Nitrogen balance (nitrogen intake, nitrogen absorbed, nitrogen retained and nitrogen retained as % intake) in Yankasa lamb rams was significantly (P<0.05) affected by PTLM and PTPM inclusions across the dietary treatment. Fitting into methane emission models, for model 1, the result revealed that lamb rams fed 0% (1.52MJ/day) and for model 2, those fed 5% (4.32L/day) inclusion of PTLM had the least methane production. While lamb rams fed PTPM inclusions were significantly (P<0.05) affected for model 1 and model 2 with those fed 5% (1.55MJ/day) and 0% (11.24L/day) inclusion levels respectively having the least methane production. The pH and total volatile fatty acid were not significantly (p>0.05) affected across the dietary treatment of PTPM inclusions but significant (p<0.05) effect was recorded for the ammonia nitrogen. The cost of the diet reduces with increasing PTLM and PTPM inclusions although best performance was observed among animals fed 5% inclusion level of PTLM and PTPM respectively in this study. PTLM and PTPM at 5% inclusion in a complete diet can be used to alleviate the problem of feed scarcity in terms of quantity and quality in the dry season period and also to enhance efficient performance of Yankasa lamb rams. Furthermore, the inclusion of PTLM and PTPM in diet of Yankasa lamb rams decreased quantity of methane released into the environment.