Trans pars plana vitrectomy with air-fluid exchange was performed on 29 selected cases of primary rhegmatogenous retinal detachment in which scleral buckling would be the usual surgical approach. The group contained 20 phakic eyes, two aphakic eyes, and seven pseudophakic eyes; the macula was detached preoperatively in 17 eyes (66%). The reattachment rate after one operation was 79% (23 of 29 eyes); after two operations this increased to 93% (27 of 29 eyes). Visual acuities of 20/50 or better were achieved in 22 of 27 successfully treated cases (81%). Vitrectomy without scleral buckling may allow retinal reattachment with excellent visual results in selected cases of primary rhegmatogenous retinal detachment.