Experimental urinary bladder tumours have been proposed as a useful model for the study of urinary bladder carcinogenesis, as well as for evaluating new therapeutic strategies. Consequently, the administration of chemical carcinogens is one of the most commonly used methods for inducing urinary bladder tumours. N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) is, undoubtedly, the most-used urothelial chemical carcinogen. BBN belongs to the nitrosamine family, a wide group of alkylating agents that are able to induce bladder tumours in laboratory animals. Depending on the animal species, the spectrum of urothelial lesions induced by BBN varies, but is similar to those observed in humans. BBN has a high propensity to induce mutations affecting the expression of genes such as p53, RAS and H19 among others. The aim of this study was to review BBN as a urothelial tumour inducer, taking into consideration its chemical characteristics, properties and spectrum of lesions induced, as well as its possible applications.