Stage T1Hg bladder cancer should be considered an aggressive and potentially lethal disease. The importance of initial re-resection to identify unrecognized muscle-invasive disease is significant. Most patients with high-risk disease are candidates for initial bladder salvage with intravesical bacillus Calmette-Guerin vaccine for immunotherapy, a procedure with a high survival rate; however, failure of the procedure may result in a guarded prognosis. Even after apparent success, patients should be informed of the risks of the disease progressing to muscle-invasive or metastatic disease and the need for vigilant monitoring. Despite optimal management, a significant number of patients relapse or progress to invasive disease requiring cystectomy. This review provides insight into the optimal management of T1 high-grade bladder cancer.