The purpose of this study is identifying lymphocele’s risk factors after renal transplantation. During 20 years (between 1986 and 2008), 377 renal transplantations were performed in our institute. Thirty cases of lymphocele were detected (8%). We have analyzed the different risk factors that can correlate with this complication by reviewing the different parameters of donors, receivers, and the intervention. A statistical study was made. Five risk factors of lymphocele were identified: age of 35 years or more, cadaver kidney, ischemia more than 24 hours, immunosuppressive treatment: mycophenolate mofetil (Cellcept®) or ciclosporin. The only significant and independent risk in the multifactor analysis was the cadaver origin of the transplanted kidney. We have noted in our study that the cadaver origin of the transplanted kidney may play an important role in the genesis of lymphocele after renal transplantation. A good preparation of the cadaver kidney and the ligation of its lymphatic vessels can help to reduce this complication. This should be confirmed in larger series.