The pharmacological actions of the dried venom of the Cape cobra (Naia flava) have been studied.The minimum lethal dose for various animals has been determined, and the symptoms produced in the frog, cat, and rabbit described.The venom has a digitalis‐like action on the circulation.Respiratory failure is the usual cause of death. In the rabbit this is largely due to a curare‐like paralysis which is not seen in the cat.The venom has a direct action on involuntary muscle, contraction being followed by relaxation. Slight hæmolysis of red‐blood cells occurs in vitro. Lengthening of the coagulation‐time following lethal injections of venom occurs in the cat but not in the rabbit.The blood‐sugar of the rabbit is raised.Non‐toxicity of the venom via the alimentary canal is to be attributed to very slow absorption and perhaps also to destruction of the venom in the large gut.Solutions of the venom slowly deteriorate on keeping.