Background: Cushing disease (CD) represents the principal cause of endogenous hypercortisolism. The first-line therapy of CD is surgical removal of the ACTH-secreting pituitary adenoma, which is generally followed by adrenal insufficiency (AI). Objective: To analyze the recovery of AI in patients with CD after pituitary surgery in relation with recurrence and persistent remission of CD. Patients and Methods: We performed a retrospective analysis of patients with CD who met the following inclusion criteria: adult age, presence of AI 2 months after the surgical intervention, and a minimum follow-up of 3 years after the surgical intervention. Results: Sixty-one patients were followed for a median of 6 years. Ten (16.4%) patients recurred during follow-up. The patients who restored adrenal function did so after a median time of 19 months, with a significantly shorter time in the recurrence group (12.5 vs. 25 months, p = 0.008). All 10 patients who recurred recovered their adrenal function within 22 months. The recovery rate of AI in the persistent remission group was 37.3% (19/51) at 3 years and 55.8% (24/43) at 5 years. In all patients the duration of AI was negatively associated with disease recurrence. Conclusion: The duration of postsurgical AI in patients with recurrent CD is significantly shorter than that in patients with persistently remitted CD, and this parameter may be a useful predictor of recurrence. Patients showing a normal pituitary-adrenal axis within 2 years after surgery should be strictly monitored as they are at higher risk of disease relapse.