OBJECTIVE Natural history of young patients with bladder cancer has not yet been known. So this study aimed to understand characteristics and prognosis of patients less than 40 years with bladder cancer. METHODS We retrospectively analyzed 42 patients (group 1) less than 40 years with bladder cancer followed up for 6 months at least from October 1998 to January 2010. As controlled group (group 2) consisted 44 patients of 60 years or more who had same condition as above mentioned from January to December 2009 was set. Tumor size and number, pathological results, urine cytology results and recurrence rate were reviewed. RESULTS The mean ages and the gender distribution in the two groups showed no difference. Tumor size (P = 0.021) and number (P = 0.016) in group 1 was smaller than control. The proportion of muscle invasive type was not significant, but pTa in group 1 was occupied larger portion than group 2 (P = 0.01). Group 1 had more low grade cancer (P = 0.013), and lower recurrence rate (7.1%) than group 2 (38.6%) (P = 0.001). In addition, the mean recurrence free duration of group 1 and 2 were 37.7 ± 6.3 and 9.9 ± 2.5 months, respectively. Group 1 showed later relapse than group 2 (P = 0.002). No progression in stage at recurrence was in group 1, but 1 case had progression in group 2. In grade, 1 case was worsen in group 1 and 3 cases were worsen in group 2.