Transurethral resection (TUR) is the most frequent surgical treatment for symptomatic benign prostate hyperplasia (BPH). Prostate size is a significant factor for choosing TUR versus prostate adenomectomy. Analysis of flowmetry results obtained with TUR in 203 patients, based on weight of resected prostate tissue. Flowmetry was performed prior to TUR and prostate size was estimated with transabdominal ultrasound. Prostate tissue was weighed after TUR and a new flowmetry was performed 6 months after treatment. Mean weight of resected tissue was 31.34 g. When all flowmetry parameters analyzed pre-and post TURs were compare, there were significant differences (p < 0.001). Increased maximum flow (Qmax) and increased mean flow (Qmed) occurred in 91.7% and 96.31% patients, respectively. Mean increase of post-surgical Qmax was significantly higher (p > 0.01) in patients with Qmax prior to surgery lower than 8 ml/s. No significant correlation was demonstrated between prostate volume measured by ultrasound or resected prostate tissue and increased post-surgical Qmax. TUR improves flowmetry parameters, mainly in patients with pre-surgical Qmax lower than 8 mL/s. Extensive prostate resection does not appear to improve the flowmetry results obtained with a sufficient functional TUR.