Objectives: The objectives are to examine the adrenal gland tumors of patients that were operated at the Clinical Hospital Center Osijek in the period from the introduction of the BIS in 2016 to March 2019 in order to test whether there is a difference in the location, size and pathohistological finding of the tumor between examinees of both gender and age considering gender, left – to – right localization and unilateral – bilateral localization and tumor size. The draft of the study: The study was conducted as a cross – sectional with historical data. Examinees and Methods: The examinees are patients of both sexes diagnosed with adrenal tumors who were operated at the Clinical Hospital Center Osijek in the period from the introduction of the BIS in 2016 to March 2019. Archive of the CHC Osijek was used in this paper. The results were processed by the statistical program STATISTICA 12.5.192.7 Results: Adrenal tumors are more predominant in females. No statistically significant differences were found examining the difference in tumor size considering gender, left to right localization, and unilateral – bilateral localization. Correlating age and size revealed that younger patients were more likely to have a larger tumor. Also, there was no significant difference in left to right localization, but statistically significantly higher incidence of unilateral tumors compared to bilateral incidence. Benign tumors are significantly more common than malign Conclusion: There was a statistically significant difference in the incidence of tumors regarding the gender, pathohistological diagnosis, and unilateral – bilateral localization but no difference was observed in the left to right localization and the size. Correlating age and size revealed that younger patients were more likely to have a larger tumor.