© 2017 Elsevier Inc.Background To report the initial and long-term remission rates and related factors, secondary treatments, and outcomes of a series of patients with Cushing disease (CD). Methods We included 147 consecutive adult patients with CD who underwent primary transsphenoidal surgery (TSS) between 1998 and 2014 in this study. Eighty-two were followed up in the Cerrahpasa Medical Faculty Endocrinology and Metabolism outpatient clinic. Patients were requested to attend a long-term remission assessment; 55 could be contacted, and data for the remaining 27 patients' last visit to the outpatient clinics were reviewed for early and late remission. Six patients were excluded from the study. Magnetic resonance imaging (MRI) findings and pathologic results including mitosis, Ki-67 levels, and P53 in immunostaining of all patients were evaluated. Results Data of 82 patients with CD with an average age of 36 years [interquartile range: 29–47] were analyzed with a mean follow-up of 7.5 years [interquartile range: 5–10]. Overall initial remission rates were 72.3% after TSS. Among the 82 patients, 16 patients had Gamma Knife radiosurgery and 7 patients underwent adrenalectomy. After these additional treatments, the long-term remission rate was found as 69.7%. The highest remission rates were with microadenomas. Recurrence was most frequently seen in patients without tumor evidence on MRI. Patients with high Ki-67 levels had higher recurrence rates in long-term follow-up (P = 0.02). Conclusion Life-long follow-up for patients with CD seems essential. Undetectable tumors on MRI before TSS and high Ki-67 immunopositivity were found as risk factors for tumor recurrence.