Fourty-four CT-guided adrenal biopsies were performed on 43 patients aged 12-74 years old (mean 57 years). The results (benign adrenal tissue, malignant tissue, and nondiagnostic) were compared with outcomes. Diagnostic samples were obtained in 86% of patients. Among the 37 proved cases with diagnostic results (10 benign, 27 malignant), there were 26 true-positives, 1 false-negatives and 10 true-negatives. CT-guided adrenal biopsy had an accuracy of 82%, a sensitivity of 96%, a negative predictive value of 83%. In the 6 patients with nondiagnostic samples 1 mass proved malignant and two masses proved benign. Seven minor complications occurred in 7 patients (6 pneumothoraces and 1 retroperitoneal hemorrhage). CT-guided adrenal biopsy is a simple safe and well tolerated technique. In oncologic patients, obtaining benign adrenal tissue was highly predictive of benignity.