Pituitary adenomas result in clinical sequelae and accelerated mortality due to central mass effects or pituitary hormone hypersecretion and/or insufficiency. The low annual incidence and prolonged natural history of these rare tumors has hindered efforts to evaluate long-term clinical outcomes. Care of these patients is often provided by larger tertiary specialist referral centers. A novel evidence-based computerized pituitary tumor registry was developed to systematically evaluate epidemiological, biochemical, and clinical outcome data. Retrospective registration of 371 patients [99 clinically nonfunctioning tumors (CNFTs), 176 acromegalics, and 96 prolactinomas] with radiological, biochemical, and clinical evidence of pituitary tumors was performed. Analysis of this primarily specialist-referred population revealed a female predominance among CNFT (60%) and prolactinoma (69%) patients. Males had a significantly greater frequency of macroadenomas than females for CNFTs (92% vs. (68%) and for prolactinomas (74% vs. 40%). Males with prolactinomas also had higher mean pretreatment serum PRL levels (1206 vs. 219 ng/mL). Concurrent hyperprolactinemia was present in CNFT (47%) and acromegaly (33%) patients. Radiographic cure, defined as absence of visualized tumor, was achieved in 21% of CNFTs, 34% of acromegalies, and 21% of prolactinomas. Biochemical remission, defined by normalization of hormonal tumor markers, was observed in 35% of acromegaly and 39% of prolactinoma patients in the registry, thus reflecting the tertiary referral patterns. Nine premature deaths (patients aged < or =65 yr) occurred in the acromegaly subpopulation, whereas no premature deaths were encountered in nonacromegalic patients. In conclusion, this unique and comprehensive pituitary tumor registry enables identification of diagnostic and prognostic markers and evaluation of long-term clinical outcomes. Prospectively, this registry will improve therapeutic guidelines and cost-effective pituitary tumor management.