ABSTRACT Objectives To compare the surgical outcomes of men with bladder outlet obstruction (BOO) due to benign prostatic obstruction (BPO) to those with detrusor underactivity (DU) or acontractile detrusor (DA). Materials and Methods This retrospective, IRB approved study included men who underwent BPO surgery for refractory LUTS or urinary retention. Patients were grouped based on videourodynamic (VUDS) findings: 1) men with BOO, 2) men with DU and 3) men with DA. The primary outcome measure was the Patient Global Impression of Improvement (PGII). Secondary outcome measures included uroflow (Qmax), post-void residual volume (PVR) and the need for clean intermittent catheterization (CIC). Results One hundred and nineteen patients were evaluated: 1) 34 with BOO, 2) 62 with DU and 3) 23 with DA. Subjective success rate (PGII) was highest in the BOO group (97%) and those with DU (98%), while DA patients had a PGII success of 26%, (p<0.0001). After surgery, patients with BOO had the lowest PVR (68.5mL). Fifty-six patients (47%) performed CIC pre-operatively (47% of BOO, 32% of DU and 87% of DA patients). None of the patients in the BOO and DU groups required CIC post operatively compared to16/23 (69%) of patients in the DA group (p<0.0001). Conclusions BPO surgery is a viable treatment option in men with presumed BOO and DU while DA is a poor prognostic sign in men who do not void spontaneously pre-operatively.