Introduction: We aimed at evaluating the incidence of lymphoceles, a common complication after radical retropubic prostatectomy (RRP), at a high volume centre, define risk factors and assess the clinical outcome. Materials and Methods: 454 patients receiving RRP and pelvic lymph node dissection were assessed for postoperative lymphoceles using the ultrasound method. Findings were correlated to clinical parameters from a database (age, BMI, initial PSA, number of lymph nodes removed, prostate weight, duration of surgery, hospital stay, duration of catheterisation) and possible unconventional risk factors using meteorological data. Results: Overall, 15.4% developed a lymphocele, 2.6% had a symptomatic lymphocele requiring treatment. The mean size of the lymphoceles requiring treatment was significantly higher (400 vs. 115 ml). Patients with lymphocele stayed longer in hospital. No correlation could be found between the clinical parameters and the risk for lymphoceles. Functional results in terms of urinary continence were similar. The assessment of meteorological risk factors showed a correlation of lymphoceles with air humidity. Conclusion: Lymphoceles are common after RRP, but few cases require intervention. There is no reliable clinical predictor for the risk of lymphocele development. Data sets have been published suggesting several risk factors but may be subject to statistical error like in the case of the meteorological predictors in this study.