PURPOSE: To assess the long-term outcomes of tension-free vaginal tape (TVT) for stress urinary incontinence (SUI) with intrinsic sphincter deficiency (ISD) and to identify influencing factors for failure in these cases. METHODS: A total of 136 women who underwent TVT procedures with minimum follow-up duration of 3 years were included in the study. Patients were divided into two groups (non-ISD and ISD groups) based on preoperative urodynamic studies. Patient outcomes were assessed from retrospective chart review and telephone research. Cure was defined as the subjective resolution of SUI in any circumstances. Improvement was defined as the subjective improvement of SUI without complete resolution. Failure was defined as the subjective lack of improvement of SUI. Patients in ISD group were subdivided into two subgroups (cure and non-cure groups) and were compared to identify influencing factors for TVT procedure failure. RESULTS: Eighty-nine patients were in non-ISD group, and 47 in ISD group. The mean follow-up durations were 50.3+/-9.2 and 49.7+/-9.7 months, respectively. Subjective cure rate was 75.3% for non-ISD group, and 76.7% for ISD group (P>0.05). Improvement rate was 6.7% for non-ISD group, and 2.1% for ISD group (P>0.05). Satisfaction scores was 3.8+/-1.2 points in the non-ISD group, and 3.5+/-1.2 points in ISD group (P>0.05). In ISD subgroups, VLPP was 41.9+/-12.0 cmH2O for non-cure group, and 50.5+/-8.6 cmH2O for cure group, and was the only factor that showed significant statistical difference between the two subgroups (P=0.011). CONCLUSIONS: With our long-term results, TVT is an effective treatment even in women with ISD. However, ISD patients with low VLPP should be counseled carefully about TVT outcome.