OBJECTIVE Persistent retinal detachment following scleral buckling may be caused by persistent open retinal tears with a large amount of subretinal fluid, despite proper positioning of the buckle. In this study we evaluated the effectiveness of supplemental pneumatic retinopexy in flattening of the detached retina. METHODS During 1990-1994 twelve cases of persistent retinal detachment following scleral buckling operation with appropriate position of the buckle, underwent supplemental gas injection. RESULTS Reattachment of the retina with complete absorption of the subretinal fluid was observed within 24-48 hours from the gas injection in all eyes. Three eyes redetached and required additional operations. At the end of the follow-up (mean 16 months) the retina was attached in all eyes, and the visual acuity was 20/120 or better in 11 eyes, and 20/30 or better in 7 eyes. No complications were observed. CONCLUSIONS Pneumatic retinopexy for persistent retinal detachment, following scleral buckling, is effective in obtaining fast flattening of the retina and achieving good visual results.