Abstract: Objective: To assess the clinical outcome of a strategy of conservative monitoring of patients with nonfunctioning pituitary adenomas (NFPA) after pituitary surgery and in patients without surgery. Design: Retrospective study of outcomes, using a clinical information system. Patients: An unselected, clinical series of patients seen in a single centre between 1989 and 2015. Measurements: Review of clinical information system data to obtain details and dates of surgery, radiotherapy, pituitary imaging and outcomes. Results: We identified 190 cases of NFPA. Trans‐sphenoidal surgery (TSS) had been performed as primary therapy in 132 cases (all macro‐adenomas). At a mean 7.6‐years follow‐up after TSS without immediate pituitary radiotherapy, recurrence occurred in 10.7% of cases with no visible postoperative residual adenoma, 38.8% with intrasellar and 66.7% with extrasellar residuum. Recurrence was defined as growth of residual tumour requiring intervention. On survival analysis, at 10 years, recurrence‐free survival was 75% in patients with no residual tumour and 40% with intrasellar residuum. Recurrence occurred in 12.5% of 24 patients who had received postop radiotherapy. Patients were monitored conservatively without initial surgery in 65 patients. After a mean of 5‐year monitoring, only 20% required intervention during follow‐up (18.5% TSS) and 30.8% died of nonpituitary causes during follow‐up. Conclusion: This study suggests that a conservative approach may be safe and appropriate in patients with NFPA if followed up with appropriate imaging surveillance, whether postoperative or without primary surgery. [ABSTRACT FROM AUTHOR]