Abstract: Aqueous and ethanolic crude extracts and fractions of Khaya senegalensis stem barks were investigated for their antioxidant activities. Their ability to act as radical scavengers have not been previously reported and was investigated using 1,1 diphenyl-2-picryl-hydrazyl (DPPH), a stable free radical in comparison with Rutin and Quecetin as antioxidant standards. The study shows that all extracts and fractions are able to scavenge significantly free radicals of DPPH. The IC50 are, respectively 9.82 µg mL•1 for defatted extract; 7.42 µg mL•1 for Rutin (Standard); 7.33 µg mL•1 for lyophilised aqueous extract; 6.01 µg mL•1 for the fraction F1 of lyophilised aqueous extract; 4.70 µg mL•1 for ethanolic extract; 4.37 µg mL•1 for the fraction F2 from methanolic crude extract of stem barks and 2.58 µg mL•1 for Quercetin (Standard). Lyophilised aqueous extract activity is closely related to that of Rutin but less than Quercetin. Fractions can play a pivotal role in the antioxidant activity of crude lyophilised aqueous and alcoholic extract of stem barks of Khaya senegalensis.