Nowadays, incidental anatomical variants are frequent findings, due to the widespread diffusion of cross-sectional imaging. This case report illustrates a fairly uncommon anatomical variant, that is, the copresence of left inferior vena cava and retroaortic right renal vein reported in a 46-year-old lady, undergoing a staging CT for breast cancer. Although the patient was asymptomatic, the authors highlight potential risks related to the above-mentioned condition and the importance of correct identification and diagnosis of the findings.