The ocular prognosis of Behçet's disease was assessed in 31 French native patients with ocular involvement. The mean follow-up time was 6 years. Ophthalmologic manifestations revealed the disease in 61% of patients, and it was the first symptom in 29%. Two groups of patients could be identified: the minor forms (23%) which remained stable with colchicine alone and the severe forms (77%) which required steroid (32%) and/or immunosuppressive (45%) therapy. In the severe forms, 32 eyes were unchanged, 4 eyes showed improvement, and 12 eyes showed deterioration in visual acuity. Positivity of HLA B5, sex and complete form of the disease were not predictive factors of ocular involvement, or of its seriousness. At 6 years, 16% of the eyes (versus 14% at the beginning) had a visual acuity less than 1/10, and 71% (versus 74% at the beginning) had a visual acuity greater than 8/10. A close collaboration between ophthalmologists and internists allows a good visual prognosis in Behçet's disease.