OBJECTIVE To evaluate the causes of failure to find retinal breaks, the anatomical and functional outcomes of patients with rhegmatogenous retinal detachment (RD) without detectable breaks (Group I), to compare the results with detectable breaks (Group II). METHODS Forty-five out of 258 eyes that had RD without detectable breaks were analysed retrospectively. RESULTS The causes of failure to find retinal breaks were aphakia/pseudophakia in 22 eyes, small pupil without any eye disease in four eyes, corneal opacity in two eyes, cataract in two eyes, vitreous haze in two eyes, choroidal detachment in one eye, and unknown cause in 12 eyes. After a single scleral buckling procedure, anatomical re-attachment of the retina successfully occurred in 62.2% of group I and 78.9% of group II patients. After repeated surgery, final anatomical success rates were 87.2% and 90.2%, respectively. The best corrected visual acuity was 6/60 or better in 53.9% in Group I and 52.5% in Group II. CONCLUSIONS The main cause of failure to find the retinal break was aphakia or pseudophakia. Although the rates of retinal reattachment in eyes without detectable breaks in primary buckling surgery was lower than detectable breaks and reoperations were required more frequently, final success rates were satisfactory and similar in both groups.