Functional, antinutritional, antioxidant and elemental compositions of full-fat sample (FFS) and defatted sample (DFS) Mucuna sloanei (Ukpo) seed were investigated using standard analytical techniques. The results of functional properties (%) in full fat and defatted seed flours were as follows; foaming capacity (6.00 ± 0.04 and 30.30 ± 0.15), foaming stability (1.10 ± 0.00 and 24.00 ± 0.20), water absorption capacity (50.00 ± 0.05 and 70.00 ± 0.05), oil absorption capacity (19.50 ± 0.50 and 21.75 ± 0.15), emulsion capacity (41.58 ± 0.14 and 44.12 ± 0.08), emulsion stability (39.61 ± 0.23 and 34.31 ± 0.11), least gelation concentration (0.03 ± 0.00 and 0.10 ± 0.00) g/cm3 and bulk density (0.77 ± 0.01 and 0.91 ± 0.00) g/cm3 respectively. The antinutrient analysis of full fat and defatted seed flours in mg/g showed glycoside with the highest value to be (23.60 ± 0.13 and 41.18 ± 0.05), phytic acid (20.15 ± 0.07 and 13.15 ± 0.07), oxalate (7.11 ± 0.02 and 0.47 ± 0.12), phytin P (5.68 ± 0.38 and 3.70 ± 0.14) and tannins (0.37 ± 0.01 and 0.47 ± 0.02). Potassium was found to give higher values in the two samples with defatted sample having the highest value. The antioxidant analysis of the full fat and defatted seed flours showed DPPH to be (33.08 ± 0.06 and 35.13 ± 0.03) %, FRAP (48.93 ± 0.11 and 49.03 ± 0.08) mg/g, phenol (4.16 ± 0.07 and 5.28 ± 0.06) % and flavonoid (8.28 ± 0.00 and 3.68 ± 0.10) % respectively. From this nutritional assessment, defatted seed flour of M. sloanei could be described as a good food that can be used to supplement the existing food table in the fight against protein - malnutrition syndrome among the developing countries of the world.