Abstract Objectives Patients undergoing retropubic radical prostatectomy (RRP) may suffer from lower urinary tract symptoms (LUTS). We aim to characterize LUTS and to evaluate the correlation and agreement between uroflowmetry and the International Prostate Symptom Score (IPSS) in patients after RRP in two reference centers. Methods An observational multicenter prospective study was conducted between December 2015 and September 2016. Patients with at least 12-months of follow-up after RRP were included; these were evaluated with uroflowmetry and the IPSS. Results A total of 90 patients were included. The mean follow-up was of 54.6 months (standard deviation [SD] = 27.52), and the mean age was 65 (SD = 6.85) years old. The mean IPSS was 7.41 (SD = 6.29), with 33.3% (n = 54) of the patients with moderate symptoms and 6.7% (n = 6) with severe symptoms. A total of 50% (n = 45) of the patients had normal uroflowmetry. Patients with an abnormal/equivocal result in the uroflowmetry had a mean of 9.31 (SD = 7.03) points in the IPSS versus 5.51 (SD = 4.82) in patients with a normal uroflowmetry result (p < 0.01). The level of agreement between mild versus moderate-to-severe LUTS and normal uroflowmetry versus abnormal/equivocal was 61.1% (k = 0.22, p = 0.04). We found that a score ≥ 10 in the IPSS had a level of agreement of 65.6% (k = 0.31, p = 0.0004). Conclusions We consider that although the IPSS cannot replace uroflowmetry and vice versa, these tests are complementary and may be useful tools in the evaluation of patients with LUTS after RRP.