- Membership lists of professional bodies were used to establish study populations of British pathologists (1955-73) and medical laboratory technicians (1963-73). The standardised mortality ratio (SMR) for pathologists was 60 and for medical laboratory technicians 67. Twenty-seven of the 310 deaths were due to suicide. These numbers gave SMRs of 250 for pathologists and 243 for medical laboratory technicians. Suicide was the commonest cause of death in female technicians. Access to lethal chemicals at work is a possible factor explaining the high proportion of suicide by poisoning compared with the general population. Suicide rates for pathologists exceed those of all medical practitioners; similary medical laboratory have higher rates than all laboratory technicians. Excess deaths from lymphatic and haemopoietic neoplasms were noted in English male pathologists (observed 8, expected 3-3; P less than 0-01). This difference is not due to Hodgkin's disease or leukaemia and remains unexplained. No other neoplastic diseases were noted as causing excess mortality in either occupational group but a small, possibly spurious, excess number of deaths was noted for aortic aneurysm in male pathologists (observed 4, expected 1-8).