Objective: Data on the presentations and outcomes of patients with adrenal gland metastases are limited. Our objectives were to characterize the prevalence of adrenal metastases subtypes and investigate how varying clinical presentations affect disease progression, development of primary adrenal insufficiency (PAI) and mortality. Design: Single institution tertiary centre, retrospective cohort study from 1997 to 2020. Patients and Measurements: Adult patients with adrenal metastases. Clinical, radiologic and biochemical presentations and outcomes were reviewed. Results: Of 579 patients (62.3% men, median age 67 years [range 25-92]) with adrenal metastases (median tumour size of 30 mm [range 5-200]), 339 (58.5%) were discovered during cancer staging, 210 (36.3%) were found incidentally, and 29 (5.0%) based on symptoms. Tumours originated from the lung (226, 39.0%), genitourinary (GU) (160, 27.6%), gastrointestinal (GI) (79, 13.6%) and other (114, 19.7%) organ systems. Bilateral metastases were found in 140 (24.2%) patients at the time of initial diagnosis, and 249 (43.0%) had bilateral disease throughout the study course. PAI developed in 12.4% of patients with bilateral disease and was associated with larger tumour size. Median follow-up time was 14 months (range 0-232), and 442 (76.3%) patients died. Higher mortality was independently associated with older age, adrenal metastases originating from the lung, bilateral disease, and the absence of adrenalectomy. Conclusions: Adrenal gland metastases originated most commonly from lung, GU and GI malignancies. Bilateral adrenal metastases occurred in 43% of patients, and PAI occurred in 12.4% of those with bilateral disease, warranting further case detection strategies.