Abstract: Perishability is still a major problem leading to scarcity of vegetables during dry season in Nigeria. Preserving them by dehydration is a cheap solution. This study therefore investigated the effect of drying on the chemical composition of osmosised and dehydrated red bell pepper Capsicum annum (Tatase) with the intent of producing dry pepper with high chemical compositions. Sugar and distilled water were used to prepare osmotic solution (60^oBrix) inside which the red bell pepper were dipped at 40°C for 9 h at 30 min interval for the first two hours (30, 60, 90, 120 mins.) and at 1 hour interval for the remaining seven hours (180, 240, 300, 360, 420, 480 mins.), respectively. The osmosised sample was finally subjected to freeze drying, oven drying and solar drying. After drying, the proximate composition, vitamin C content and Water Absorption Capacity (WAC) of the samples were analyzed. The result of the proximate composition showed that the osmosised raw pepper contained 15.47% protein, 8.93% Ash, 11.60% fat, 0.22% crude fibre and 63.37% carbohydrate; freeze dried sample contained, 15.30% protein, 8.77% Ash, 11.52% fat, 0.16% crude fibre and 64.25% carbohydrate; solar dried sample contained 15.28% protein, 8.70 Ash, 11.58% fat, 0.20% crude fibre and 64.32% carbohydrate while oven dried sample contained 12.27% protein, 8.35% Ash, 11.38% fat, 0.21% crude fibre and 67.79% carbohydrate in comparison with the raw sample (without treatment) which contained 27.27% protein, 10.79% Ash, 15.78% fat, 0.67% crude fibre and 45.49% carbohydrate. The vitamin C and Water Absorption Capacity contents were; 150 mg/100 g and 100%v/w, 125 mg/100 g and 350% v/w, 100 mg/100 g and 250% v/w, 125 mg/100 g and 300%v/w and 200 mg/100 g and 50%v/w for osmosised raw, freeze dried, solar dried, oven dried and raw pepper samples, respectively. These results indicated that freeze drying method was the best method that resulted in less reduction of protein and vitamin C content of the pepper after drying and had the highest water absorption capacity.