The objective of this study was to evaluate intravesical gemcitabine in high-risk nonmuscle-invasive bladder cancer (NMIBC) refractory to bacillus Calmette-Guérin (BCG). This was a prospective multicentre single-arm trial. Eligible patients were those with high-risk NMIBC refractory to BCG therapy, for which radical cystectomy was indicated but not conducted because of patient refusal or ineligibility. Patients received intravesical gemcitabine twice weekly at a dose of 2000 mg/50 ml for 6 weeks, and then weekly for 3 weeks at 3, 6, and 12 months. Outcome measures were recurrence rate, time to first recurrence, progression rate and complications. Twenty patients were enrolled and included in the analysis. Median follow-up was 15.2 months. Fifty-five percent (11 patients) developed disease recurrence. Mean time to the first recurrence was 3.5 months and 45% (five patients) of recurring patients had disease progression. Overall, treatment was well tolerated. Urinary symptoms represented the primary adverse events. The role of gemcitabine used as second-line treatment in high-risk BCG-refractory NMIBC patients who refused or were unsuitable for radical cystectomy remains to be defined. Further clinical research in this area is needed.