The present study examined the pattern of presentation and diagnostic interval, i.e. number of months between first cancer symptom or sign and first medical visit, in 444 cases of urological cancer (122 of prostate cancer, 187 of bladder cancer and 135 of kidney cancer). The mean diagnostic interval was 7.6 months for prostate, 5.6 for bladder and 4.5 kidney cancer. A chance diagnosis, i.e. in absence of any symptom or sign, was reported by 16%, 8% and 18% of patients with cancer of the prostate, bladder and kidney respectively. We observed on significant differences in diagnostic intervals according to patients' demographic, sociocultural, and life-style characteristics, or tumor stage. Better quantitative and qualitative data on the pattern and determinants of delay in cancer diagnosis are clearly warranted, and the present study, although largely negative, shows the possibility of using large-scale epidemiological investigations for this purpose.