A comparison of death certificates and necropsy findings in a group of premenopausal women suggests that a number of diseases are either underdiagnosed in life. Atypical cases of intracerebral haemorrhage are frequently misdiagnosed. These occur in the frontal, temporal or parietal lobes in non-hypertensive women and may be suitable for surgical treatment. Their aetiology remains obscure. Pulmonary embolus is habitually underdiagnosed in premenopausal women and myocardial infarcts appear to be overdiagnosed. The study reemphasizes that death certificates are inaccurate and that low necropsy rates render accurate statistics of diseases in the community difficult ot obtain.