Driving a bus in urban areas is considered to be a highly stressful occupation, one which also involves exposure to air pollutants generated by motor vehicles. In order to investigate the potential health hazards associated with this occupation, the causes of dath of 376 New York City bus drivers were studied. Analyses of proportionate mortality found a significant excess due to ischaemic heart disease in drivers in both races combined (proportionate mortality ratio PMR = 1.23), and among the 58 non-white drivers (PMR = 1.72). A significantly elevated risk of death from mental, psychoneurotic and personality disorders (ICDA Ninth Revision 290–319, which includes alcoholism and narcotics abuse) was also found in the combined group (PME = 1.26) and for cancer of the oesophagus (PMS = 2.54) were significantly elevated. No cancer sites were found to be significantly elevated in the proportionate mortality analyses by race. These findings are consistent with the growing body of literature linking job strain with cardiovascular disease among bus drivers.