ABSTRACT Objective To describe the prevalence, clinical characteristics and outcome of adrenal lesions in long-term follow-up of Multiple endocrine neoplasia type 1 (MEN1) patients. Subjects and methods We retrospectively studied sixteen patients from six families of individuals with MEN1. Adrenal involvement was evaluated using clinical, biochemical and imaging data. Results Adrenal lesions were identified in nine of sixteen (56.3%) patients: seven women and two men (mean age: 52.2 years). Adrenal involvement was detected at MEN1 diagnosis in more than half of the patients. Eighteen adrenal nodules were founded (median of two nodules per patient) with mean adrenal lesion diameter of 17.4 mm. Three patients had unilateral adrenal involvement. Hormonal hypersecretion (autonomous cortisol secretion) was found in two patients. None of the patients was submitted to adrenalectomy, presented an aldosterone-secreting lesion, a pheochromocytoma, an adrenal carcinoma or metastatic disease during the follow-up. A predominance of stable adrenal disease, in terms of size and hormonal secretion, was observed. Adrenal lesions were evenly distributed between the germline mutations. Conclusion Adrenal tumours are a common feature of MEN1 that can affect more than half of the patients. Most of the tumours are bilateral non-functional lesions, but hormonal secretion may occur and should be promptly identified to reduce the morbidity/mortality of the syndrome. Periodic surveillance of these patients should be performed.