PURPOSE: To search findings that can explain the heterogeneity between Resistant and Responsive patients with birdshot chorioretinopathy. PATIENTS AND METHODS: This was a retrospective observational case series on "Responsive" versus "Resistant" birdshot chorioretinopathy. RESULTS: One-hundred-eighty and Ninety-nine patients were included in the Responsive and Resistant groups respectively. Multivariate analysis of paraclinical variables at the first visit demonstrated that mean deviation (p = .04), pattern standard deviation (p < .001), optic nerve head leakage (p = .012), large vessel leakage and staining (p = .01), and macular small vessel leakage (p = .03) were statistically significantly different between the two groups; however, at the visit preceding successful therapy, only macular small vessel leakage (p = .01) was statistically significantly different between the two groups. CONCLUSION: .Small vessel leakage in the macular area and/or optic nerve head leakage at the earliest visit might be risk factors for resistant birdshot chorioretinopathy.