AbstractBilateral symmetrical electrolytic lesions were placed in the supraoptic, ventromedial and mamillary areas in groups of albino rats weighing 50, 100, 150, 200, 250 and 300 gm.The localization of the lesions was correlated with the coordinate setting used with the stereotaxic instrument.The diagrams presented contain the data for the antero‐posterior, lateral and dorso‐ventral coordinates plotted against the body weight of the respective groups and allow the extrapolation of coordinates for other hypothalamic structu