Antidiabetic activity of crude extract of leaves of Talauma ovata St. Hil. (Magnoliaceae) was analysed as part of a general pharmacological screening of this plant. Chemical analysis demonstrated the presence of phytosteroids, saponins, alkaloids and tannins in the crude extract. Pharmacological studies failed to demonstrate hypoglycemic effect of this plant in normoglycemic, hyperglycemic or alloxan-diabetic rats. The low LD50 obtained for this plant strongly suggests that its consumption by the population may be hazardous.