This research was carried out to investigate proximate and in-vitro gas production of sweet potato (Ipomoea batatas) peels supplemented with urea-sulphur mix fed to sheep. Four iso-nitrogenous and iso-caloric diets (T1, T2, T3 and T4) were formulated which contained sweet potato peels with varying levels of urea and sulphur; T1 (control), T2 (0.2% Sulphur), T3 (0.3% urea), T4 (0.1% sulphur + 0.15% urea). The rumen content was collected from the experimental sheep for the in vitro gas production and fermentation kinetics, which were estimated on 3-hourly bases for 48 hours. Data were collected on post incubation gas production, fractional rate of gas production, lag time, dry matter digestibility and proximate composition of the diets. Data collected were subjected to one-way Analysis of Variance at 5% level of probability. Chemical composition of the diets and in vitro gas production were not influenced (P>0.05) by urea-sulphur mix supplementation. The dry matter digestibility of the diets was significantly (P<0.05) highest in the control while least was from diet with 0.1% sulphur and 0.15% urea. The volumes of carbondioxide gas obtained were significantly (P<0.05) different with the highest and least volumes in control and diet with 0.1% sulphur and 0.15% urea mixture, respectively. The study showed that sole supplementation of urea and sulphur improved dry matter digestibility while urea-sulphur combination reduced carbondioxide production.