Citrullus vulgaris, traditionally known as “Niri” is a traditional seed used for the preparation of stew, soup and other traditional foods especially by inhabitants of the northern sector of Ghana. Despite it usage for centuries, less attention has been paid to it nutrient composition in Ghana. Therefore, this study was carried out to determine the proximate and mineral compositions of Citrullus vulgaris (“Niri”) seed and it processed materials (raw and roasted purees, raw and roasted chaffs). Proximate and mineral compositions were done according to procedures in the International Association of Official Analytical Chemist. There were statistical differences (P<0.05) in all the proximate components examined. The ash (2.27%), fat (42.27%) and protein (20.30%) contents of the whole “Niri” seed were significantly higher (P<0.05) than the processed seeds. Carbohydrate and moisture contents were significantly highest in raw chaff (69.85%) and roasted puree (53.60%), respectively compared to the whole “Niri” seed and other processed products. The calcium content of the whole “Niri” seed and its processed product did not differ significantly (P>0.05) from the processed products. However, the iron (4.08mg/g), potassium (32.96mg/g), magnesium (28.35mg/g) and zinc (0.56mg/g) contents of the whole “Niri” seeds were significantly higher than the processed products. This study indicated that protein, carbohydrate, fat, water, calcium, iron, potassium, magnesium and zinc are present in both whole “Niri” seeds and in it processed form. Therefore, they have the potential to be used as ingredient for further processing or for non-tradition food.