The research work covers the Pharmacognostic and Biological studies of the aqueous extract of the rhizome of Cochlospermum planchonii, Hook F (family: Cochlospermaceae) which is claimed by the Hausa in the Northern Nigeria to be used traditionally for the relief of pain. Macroscopical, microscopical and chemomicroscopical studies have been carried out on the whole rhizome, powdered samples and anatomical sections. Characteristic pharmacognostic features of the plant observed were calcium oxalate crystals, sclerenchymatous fibres, reticulate vessels, numerous starch grains, sclereids and parenchyma cells. The peculiar feature being isodiammetrically shaped isolated sclereids with thick walls and lignified lumen showing striation. This could be used as indices for identification of the plant. Quantitative evaluations were also carried out. The moisture content, alcohol soluble extractive value, water soluble extractive value, total ash value and acid insoluble ash were found to be 7.20%, 2.91%, 3.92%, 16.04% and 8.00% respectively. These can serve in qualifying and differentiating the plant. The various phytochemical tests revealed the presence of carbohydrates tannins, alkaloids, flavonoids, terpenes and sterol, saponins and cardiac glycosides which could be responsible for the pharmacological action of the plant. The plant was safe orally on acute toxicity investigation. There was no observable LD50. The result of the analgesic and anti- inflammatory activities of the extracts showed a significant and dose dependent activity when compared to the untreated control group at P<0.05. This justifies the use of the plant in ethno-medicine for the treatment of pain.