Large adrenal cysts usually occur in the fifth and sixth decades of a patient's life but are rare in the first two decades. This paper presents the clinical, cross-sectional imaging, surgical, pathological and follow-up data of three teenage girls with large adrenal cysts. Two had vague upper abdominal pain and, in the other, the cyst was found incidentally. The cysts were surgically removed in two patients, while in the third, follow-up imaging has shown no change in the cyst over a 4-year period, suggesting that conservative management is a reasonable option.