Introduction: A correlation between urothelial bladder tumor incidence and exposure to various occupational toxic factors was established for more than a century. The aim of our study was to establish the relationship between these two features.

Materials and methods: We analyzed one hundred consecutive bladder tumor patients treated in “Sf. Ioan” Clinical Emergency Hospital, Department of Urology. These cases were studied concerning their occupation and pathological findings.

Results:We identified 58 patients having potential urothelial bladder tumors inducing occupations: dye industry, motor vehicle drivers and miners. Among these patients, the incidence of muscle invasive tumors was of 33%, of the high-grade tumors was of 69%, of the multiple tumors was of 60% and of the associated CIS lesions was of 38%. All these rates were significantly lower in the non-occupational hazard group: 12%, 26%, 29% and 14% respectively.

Conclusions: Exposure to occupational toxic factors seems to influence the evolution of urothelial bladder tumor into more aggressive patterns. Further studies in this regard are necessary.