The investigation was based on 405 men and 482 women. In all cases the optimal weight depending on the metric index and the body weight estimated by means of the Brocaindex was calculated. The comparison of all data revealed the following: 1. Persons deceased have always a lower body weight than living persons of equal age, constitution and sex independant of the method used. That means that diagnosis of generalized adipositas is more difficult in persons autopsied than in persons living. 2. The calculation of the optimal weight and of the Brocaindex does not yield the same results. In the majority of the cases the optimal weight is lower. Therefore, the pathologist must know which method of evaluation of body weight the clinician used. 3. The optimal weight depends on the constitution. This applies to persons deceased as well as living. 4. There is a statistical correlation between postmortem optimal weight and basic disease. For the dicision whether generalized adipositas or extreme cachexia being the cause of death the optimal weight should be considered.