Objectives To compare patient and tumour characteristics at presentation from two large bladder cancer cohorts, with recruitment separated by 15-20 years To identify significant differences in the West Midlands' urothelial cancer of the bladder (UCB) population during this period. Patients and Methods Data were collected prospectively from 1478 patients newly diagnosed with UCB in the West Midlands from January 1991 to June 1992 (Cohort 1), and from 1168 patients newly diagnosed with UBC within the same region from December 2005 to April 2011 (Cohort 2). Gender, age, smoking history, and tumour grade, stage, type, multiplicity and size at presentation were compared using a Pearson chi-square test or Cochran-Armitage trend test, as appropriate. Result Cohort 2 had a higher proportion of male patients (P = 0.021), elderly patients (P <0.001), grade 3 tumours (P <0.001), Ta/T1 tumours (P = 0.008), multiple tumours (P <0.001), and tumours of ≤2 cm in diameter (P <0.001). Conclusions There were significant differences between the cohorts. These differences are potentially explained by an ageing population, changes in grading practices, improved awareness of important symptoms, improved cystoscopic technology, and reductions in treatment delays. Regional cohorts remain important for identifying changes in tumour and patient characteristics that may influence disease management in the UK and beyond. © 2013 BJU International.