Analgesic nephropathy is known to have a high incidence in Australia where, following the experience in Scandinavia, reports have been published for some time recording the association between analgesic nephropathy and urothelial malignancies. The morbid anatomical features of analgesic nephropathy are now sufficiently well accepted to allow a retrospective study of unselected nephrectomies for transitional cell carcinoma of the renal pelvis and ureter, in order to assess the incidence of analgesic-type changes in this well defined group of malignancies. The records of a large general histopathology department between 1972-1978 were searched and 24 consecutive transitional cell carcinomas in these sites treated by nephrectomy were selected for study. Of these, 21 were suitable for assessment and on review were shown to comprise II cases with papillary changes acceptable as analgesic in type and five which were suggestive of early analgesic change. Of these 16, seven were female, only two were known analgesic abusers and five were recorded as consuming analgesics on a regular basis. These findings suggest that analgesics may play a significant role in the pathogenesis of urothelial malignancy in the general population.