Upper tract urothelial carcinoma (UTUC) comprises <5% of all urothelial cancers. A certain proportion of patients with UTUC will develop secondary bladder urothelial cancer (BUC). This paper has retrospectively examined records obtained from several cancer USA population-based registries of more than 5000 patients with UTUC diagnosed during the 30-year period from 1975. Just less than 5% of these patients have developed secondary BUC with male and non-white ethnicity predominance, the majority of those (>90%) have occurred within the first five years since UTUC diagnosis. It was also noted that larger tumours and those located in the ureter have more likelihood of recurring in the bladder. The rates of secondary BUC following UTUC have remained stable over 30 years with a tendency to occur within an average of two years after the initial UTUC diagnosis. Interestingly, tumour grade has not been shown to affect the probability of developing secondary BUC in contrast to primary BUC. This study has several strengths including the high number of patients studied over a long period of time. That has resulted in a high level of evidence towards understanding the natural history of UTUC, which will help urologists and uro-oncologists in planning follow-ups for patients with the disease. The authors, however, have recognised several limitations rising from the lack of details of data obtained from the patients’ registries.