Tru-cut biopsy post mortems were compared with the standard full autopsy at a large city mortuary. Subjects consisted of coronial cases excluding suspicious deaths, obvious trauma cases and children under the age of 14 yrs. The following comparisons were made: the ability to collect tissue from each of the organs; any abnormalities detected on histology; correlation of the Tru-cut biopsy results with the results of the conventional post mortem; and determination of cause of death with both techniques. Twenty-one cases were examined by both techniques. Tissue collection by biopsy varied from 100% for liver to 9.5% for kidney with heart, lung and brain giving intermediate results. The cause of death was determined in 9 cases (43%) by biopsy and in 20 cases (95%) by conventional post mortem; the cause of death was not ascertainable in 1 case. In 8 of the 9 cases (89%) where death could be determined by biopsy the cause of death was consistent with the findings of the full autopsy. The cause of death at needle biopsy examination was incorrect in 1 case (11%) compared to the findings of the standard post mortem. Clearly the needle post mortem is inferior to the conventional autopsy in determining the cause of death.