Lower urinary tract symptoms (LUTS) become increasingly common in men as they age, with over 70–90% of men aged over 80 experiencing these issues. Detrusor underactivity (DUA) is characterised by a weakened bladder contraction, leading to prolonged or incomplete bladder emptying. Benign prostatic hyperplasia (BPH) patients often have both bladder outlet obstruction (BOO) and DUA, complicating treatment outcomes. Studies suggest that surgical interventions for BPH are less effective in patients with DUA. Yet, some research indicates no significant difference in surgical outcomes between patients with and without DUA. Previous studies showed long-term surgical improvements in BPH patients with DUA, although subjective and objective outcomes did not always align. This study aims to evaluate the midterm effects of holmium laser enucleation of the prostate (HoLEP) in BPH patients with DUA. HoLEP has been a common surgical procedure for the last 20 years, with advantages over traditional transurethral resection of the prostate (TURP). Despite its technical challenges, HoLEP is favoured for its efficacy, durability, and favourable risk profile. Unlike TURP, HoLEP uses a pulsed laser with excellent haemostatic and cutting capabilities, theoretically offering a lower recurrence rate. This study found no significant difference in the duration of catheterisation post-surgery between DUA and non-DUA groups. However, the re-catheterisation rate was higher in the DUA group (10.7% vs. 5.8%), likely due to lower detrusor contractility. Despite this, postoperative residual urine (PVR) was significantly reduced in the DUA group, enhancing patient satisfaction. Four patients (1.8%) in the DUA group reported worsened LUTS post-surgery, either due to new symptoms or persistent issues. Nonetheless, the overall satisfaction was high, correlating lower postoperative PVR with higher satisfaction. The study’s strengths include a large sample size of 689 patients and a prospective database, unlike smaller, retrospective studies. It also uniquely assessed postoperative satisfaction, a critical factor for BPH patients. Despite being conducted at a single centre, limiting generalisability, the study suggests urodynamic testing pre-HoLEP may not be necessary for all BPH patients, as DUA patients showed significant improvements post-surgery. In conclusion, midterm outcomes of HoLEP in BPH patients with DUA showed minimal differences compared to non-DUA patients, with overall high satisfaction in the DUA group. Further long-term research is needed to validate these findings.