Purpose: To explore factors which lead to recurrence of idiopathic orbital inflammatory pseudotumor (IOIP).Methods: Idiopathic orbital inflammatory pseudotumor in 209 cases between Jan 1,1978 and Dec 31, 1999 in our hospital was evaluated retrospectively. The comparison of clinical and pathological parameters between patients with at least one episode of recurrence and those with no recurrence at all was performed and analyzed using logistic regression method.Results: Follow-up results (with a mean follow-up time of 3.4 years, ranging from 0.5 year to 21.0 years) showed that the recurrence rate of IOIP was 41%. Sex and proptosis were associated with the recurrence of IOIP. Male gender was more likely to relapse than female counterparts, with the male being 52% and female being 25%.The severer the proptosis is, the higher the rate of recurrence. Among the clinical subtypes of IOIP, the rate of recurrence (17%) in cases with dacryoadinitis was the lowest, followed by anterior local orbital mass (44%), posterior orbital mass (54%),myositis (75%) and diffuse subtype (100%). However, the clinical subtypes did not show significant relationship with the recurrence of IOIP.Conclusions: Male gender and severe proptosis are associated with a higher recurrent rate in patients with IOIP.