A prospective study of the prevalence of gall stones at necropsy in nine towns in England and Wales showed considerable geographical variations. The age- and sex-standardised prevalence ranged from 20.6% in Ipswich to 9.2% in Wakefield. The distribution of gall stones differed from that of all-cause mortality and was negatively correlated with that of mortality from ischaemic heart disease. Socioeconomic influences related to affluence do not appear to be major determinants of the distribution of gall stones.