Introduction: With the widespread use of high-quality cross-sectional imaging, the prevalence of incidentally discovered adrenal lesions has been increasing. Accurate preoperative size estimation of adrenal nodules is vital for diagnosis and decision-making, particularly for smaller nonfunctioning nodules, as these lend themselves to the need for decision-making and follow-up. There is controversy regarding the concordance between radiological and pathological sizes of adrenal lesions, with studies suggesting that computerized tomography (CT) scans underestimate the actual size across all size subgroups and the need to apply correction formulae to determine true size. The older published literature that evaluated size discrepancies between radiological assessment and final pathologies focused mostly on larger adrenal masses at first presentation because of the low incidence of cancer in smaller nodules. Additionally, these reports are over 2 decades old now, and therefore, the accuracy of assessment of the size of adrenal masses needs to be reviewed in light of more accurate current-day modern CT scanners. We wanted to determine if modern CT scans accurately predict the size of adrenal masses. Methods: Records of all patients who underwent adrenalectomy (n = 55) from 2014 to 2024 were examined. The largest nodule diameters reported on CT scans were compared with the final pathological size. A paired two-tailed t-test was used to compare sizes. Student's t-test and single-measure intraclass correlation were used to compare individual differences. A pretest two-tailed significance level of 0.05 and 95% confidence intervals (CI) were established. A p-value of <0.05 was regarded as statistically significant. Results: Computerized tomography scans showed adrenal nodule sizes of 47 (M:F of 27:20) patients between 7 and 94 mm (largest dimension). The histopathological sizes varied from 7 to 100 mm, with our analysis showing a size discrepancy of 0–17 mm (mean: CT size: 29.5 mm vs pathological size: 29.9 mm; p = 0.68). Subgroup analysis of nodules smaller than 3 cm showed that CT underestimated mean diameter (18.4 mm) as compared to pathological assessment (19.4 mm; p = 0.33), whilst for nodules larger than 3 cm, CT scan overestimated the size of adrenal masses at 49.9 mm as compared to 49.2 mm on pathological assessment (p = 0.67). A total of 16 of the 47 patients in our series showed a 0–1 mm discrepancy between CT scan and histopathological sizes. No statistically significant size differences were seen based on laterality and different diagnosis subgroups. Radiological sizes and final pathology measurements of cases showing a difference of 4 mm and above were evaluated using a single measure intraclass correlation for absolute agreement to compare dimensions between two measurement methods, which also showed a lack of any statistical significance for 17 (underestimated: 11, overestimated: six) such cases. Conclusion: No statistically significant difference between the sizes of adrenal nodules was detected between modern CT scanners and final pathology across all subgroups. This avoids the need to apply any correction formula, as mentioned in older studies.