We report the incidence and characteristics of lymphoceles after robot-assisted radical prostatectomy (RARP). Computed tomography was performed on 79 patients one month after RARP or when symptoms appeared. The lymphocele was defined as a cystic lesion over 10 mm in diameter. Symptomatic and asymptomatic lymphoceles were identified in 25% (20/79) of all cases, and in 40.9% (18/44) of the cases with lymph node dissection (LND). Symptomatic lymphoceles were identified in 2.5% (2/79) of all cases. Lymphoceles were significantly associated with LND, pathological stage over T3, longer period of indwelling drain tube,and higher volume fluid of drain tube (p<0.05). In conclusion, lymphoceles are quiet common after RARP. However, they rarely become symptomatic.