Objective:To analyze the long-term efficacy and safety of thalidomide on refractory Crohn′s disease (CD).Methods:A total of 79 patients with refractory CD in the First Affiliated Hospital of Sun Yat-sen University treated with thalidomide were enrolled in this retrospective study from September 2005 to July 2018. Clinical effects and adverse drug reactions were recorded and assessed.Results:In this cohort,69 patients were treated with thalidomide for ≥6 months. Sixty-eight patients among the 69 patients achieved complete clinical remission and were followed up for a median 33.5 months (range, 7-110 months). Seventeen cases relapsed during follow-up. The cumulative probabilities of remaining in remission at 12, 24, 60 months were 88.6% (95% CI 80.6%-96.6%), 80.7% (95% CI 70.3%-91.1%), 53.7% (95% CI 32.1%-75.3%) respectively. Disease activity was the only variable associated with relapse risk, with a hazard ratio ( HR) of 3.559 for Crohn′s disease activity index (CDAI) ≥220(95% CI 1.213-10.449, P<0.05). Adverse reactions were recorded in 42 (53.2%) patients including12 (15.2%) leading to discontinuation of thalidomide. No serious side effects were observed in all subjects. Conclusions:This study suggests a long-term benefit of maintenance treatment with thalidomide in refractory CD.Moderate to severe patients have an increased risk of relapse. The high incidence of drug adverse reactions may restrain the clinical application of thalidomide.