Aim: The aim of the study was to determine the incidence of "positive" findings in biopsies of the normal-appearing urothelium near primary cancer and their influence on therapeutic decisions. Materials and Methods: Between January 2001 and October 2008, in 230 patients with primary bladder cancer during initial resection of tumor, we also performed random biopsy of surrounding normal-appearing urothelium. We analyzed retrospectively the number and type of positive biopsy findings and their impact on further treatment. Results: There were 40% of patients (92/230) whose normal-appearing urothelium biopsy revealed pathological findings such as tumor tissue, Tis, and dysplasia. In 24.4% of patients, the stage of the primary tumor was Ta (32/131), in 50% it was T1 stage (30/61), and in 79% T2 stage (30/38). When we assessed the grade of malignancy, we found 18% of biopsies with G1 tumors (16/88), 33% with G2 tumors (19/59), and 69% with G3 tumors (57/83). Tumor tissue that was found in the normal-appearing urothelium in biopsy specimens in 13% of patients was in stage Ta (17/131), in 16% it was T1 stage (10/61), and in 39% of patients, the tumor was in T2 stage (15/38). Pathological findings of random biopsies were crucial in changing therapeutical decisions in 4.6% (9/192) of patients. Conclusion: Biopsy of the normal-appearing urothelial tissue is easy to perform and may help in identifying patients with high risk of disease progression and recurrence. Based on our results and results from the literature we recommend this simple tool as part of the routine management during transurethral resection of primary bladder cancer.