Forty-four patients affected by poorly differentiated (G3) superficial TCC invading lamina propria (stage T1) were treated with intravesical BCG. They underwent weekly instillations of 75 mg BCG for six week after trans-urethral resection (TUR) of bladder cancer. An additional induction course was given to patients who relapsed. A maintenance course with monthly instillations for twelve months followed in complete responder patients. After the first induction course, 34/44 patients (77.2%) showed complete response. In 10 patients a second induction course was necessary, with complete response in four. After one or two induction course, 38/44 patients (86.5%) showed complete response. The maintenance course was administered to 38 patients with 35/38 complete responses. After a median follow-up of 30 months, there were 29/44 (65.9%) disease free patients, 11/44 (25%) tumor recurrences and 4/44 (9%) tumor progressions. The drug has been well tolerated with few side effects. Our data suggest that intravescical BCG after TUR is effective in the treatment of high-risk superficial bladder cancer and we believe that it can be used a first approach in treating patients affected by T1G3 bladder cancer.