OBJECTIVE: Adrenal incidentaloma is a problem that is frequently encountered clinically with the widespread use of radiological imaging methods. In this study, it was aimed to evaluate the general characteristics of patients with adrenal incidentaloma (AI). MATERIAL AND METHODS: Clinical and laboratory results of the patients who were diagnosed and followed up at the Hacettepe University Medical Faculty Hospital between 2001 and 2013 were retrospectively analyzed. RESULTS: 543 patients were included in the study. 315 (58%) of the patients were female and 228 (42%) were male (p <0.001). The mean age at diagnosis was 56.71 ± 11.79 years. Hormonal work-up demonstrated that 76.2% of the masses were non functional adenoma 11.4% were pheochromocytoma, 9.9% were defined as subclinical Cushing’s syndrome (SCS), 1.6% Cushing’s syndrome, 0.5% were hyperaldosteronism and 0.5% patient concomitant secretion of glucocorticoid, mineralocorticoid, androgen, and catecholamines. Adrenalectomy was performed in 108 patients with removal of 28 adrenocortical adenomas (26%), 15 pheochromocytoma (14%), 14 adrenocortical carcinomas (13%) and other less frequent tumor types. Operated patients were younger than the others (mean age, 54; range, 18-83; vs 57, 27-105, p <0.001). The median survival of the entire AI series was 101 months [standard error (SE): 15.1; 95% confidence interval: 71.4-130.6]. CONCLUSIONS: Adrenal incidentaloma is common in the community and relatively simple and inexpensive diagnostic methods are needed. At the first diagnosis, evaluation should be made with proper and reliable diagnostic tests. There is a need for studies comparing the data of patients who have been operated and not operated in the long period.