Adrenal venous sampling (AVS) is essential for determining the optimal treatment strategy for patients with primary aldosteronism (PA) who desire surgery. There have been only a few reports of AVS in patients with a left inferior vena cava (IVC) because it is a rare anomaly. The case of a female patient with PA in her 30s with a left IVC who underwent AVS is reported. There was difficulty cannulating the right adrenal vein using a three-dimensional, double-angled catheter designed for the right adrenal vein (Adselect type I®; Hanaco Medical, Japan) because the right IVC was absent. To overcome this difficulty, the first and second angles of the Adselect type I® catheter were reshaped into a bow-like structure, and it crossed the abdominal aorta. The right adrenal vein was successfully cannulated, and the patient was diagnosed with bilateral adrenal hyperplasia based on the results of AVS. In conclusion, the right adrenal vein in a PA patient with a left IVC is difficult to cannulate because of its anatomical features. However, a reshaped catheter can be used to successfully cannulate it.