The isolation of three crystalline substances from the chloroform extract of the root bark ofTephrosia lanceolata Grah. is described. All of them seem to be new. These substances, as also certain amorphous fractions of the chloroform extract and the subsequent alcoholic extract have been studied for their toxicity towards fish and the results are recorded. Attempts to prepare crystalline acetyl derivatives or to obtain crystalline degradation products by alkaline hydrolysis of the different fractions of the alcoholic extract have yielded negative results.