The authors report a new case of signet ring cell carcinoma of bladder whose characteristic findings are the parietal infiltration and the rapidly fatal course. Based on a review of the literature, they define the histological features of this very rare tumour (less than 20 documented cases have been reported). The pluripotent behaviour of urothelial cells appears to be the essential element in the histogenesis of this tumour type, which is very similar to gastric linitis plastica.