Right renal vein

The renal veins are of large size, and placed in front of the renal arteries.

In contrast to the left renal vein, the right renal vein , gonadal (ovarian and testicular veins), and suprarenal vein drain directly into the inferior vena cava

The left renal vein is longer than the right renal vein, and passes in front of the aorta, just below the origin of the superior mesenteric artery. It receives the left ovarian or testicular vein and left inferior phrenic veins, and, generally, the left suprarenal vein. It opens into the inferior vena cava at a slightly higher level than the right renal vein.  

Classically, the left renal vein courses horizontally between the aorta and superior mesenteric artery to join the IVC. In addition to draining the renal parenchyma, the left renal vein also drains the left gonadal and adrenal veins. In contrast, the right renal, gonadal, and adrenal veins drain directly into the IVC.