The proximate analysis, determination of nutritionally valuable minerals and the functional properties of the seed flour of African yam bean (Sphenostylis stenocarpa) were investigated. Three different colour varieties of whole seeds and their cotyledons from the same source were identified and processed for the study. The average composition of the seeds (whole grains) was as follows: protein 20.51%, fat 12.20%, carbohydrate 50.24%, ash 2.60%, fibre 6.00% and moisture 8.36%. The corresponding cotyledons contained protein 23.93%, fat 3.65%, carbohydrate 62.40%, ash 2.25%, fibre 2.07% and moisture 5.62%. The seeds were rich in potassium and phosphorus (625.43 mg/100g) and (206.35 mg/100g) respectively for whole grains while values for cotyledons were (553.6 mg/100g) and (234.161 mg/100mg) respectively. The functional properties, that is, protein solubility (PS), water absorption capacity (WAC), fat absorption capacity (FAC), fat emulsion stability (FES), lowest gelation concentration (LGC), foaming capacity (FC) and foaming stability (FS) were investigated. Heat treatment (for the preparation of cotyledons) reduced the protein solubility, fat emulsion capacity, foaming capacity, foaming stability and lowest gelation concentration while water absorption capacity, fat absorption capacity and fat emulsion stability were slightly increased.