Activation of the mTOR pathway occurs in a substantial number of advanced-stage urothelial carcinomas; for this reason, a phase I study was conducted in patients with advanced-stage tumours to investigate the combination of the mTOR inhibitor everolimus with gemcitabine and split-dose cisplatin. Treatment with this combination resulted in haematological toxicities at the lowest dose in one of three patients during the first treatment cycle, and in all patients receiving a moderate dose of everolimus. This rapid emergence of haematological toxicities precludes further use of this treatment regimen.