Bronchogenic cysts are a congenital primitive foregut-derived developmental malformation, generally occurring in the posterior mediastinum. Their development in the retroperitoneum is extremely rare. Imaging techniques, such as multidetector computed tomography (MDCT), are typically effective in the detection of these lesions. Here, we describe three cases of a retroperitoneal cyst presenting as a para-adrenal mass. Only one boy presented with abdominal pain, and the other two showed no clinical symptoms. Endocrinological evaluation of all three cases was performed, and no adrenal hormone secretion was detected. All three cases were misdiagnosed preoperatively. Each patient underwent surgery, and one symptomatic patient became asymptomatic after surgery. Pathologic examination confirmed all three masses as bronchogenic cysts. The three cases showed some similar MDCT imaging features, including a complete adrenal structure, a cystic or solid mass in the adrenal region, and no obvious enhancement. Therefore, bronchogenic cysts should be considered in the differential diagnosis of retroperitoneal masses, even though accurate preoperative diagnosis remains difficult. A contrast-enhanced MDCT scan may be useful for differentiating hyper-attenuated cysts from other soft tissue masses.