PURPOSE: Because recognition and removal of an epiretinal membrane are important in macular hole surgery, we used the scanning laser ophthalmoscope preoperatively to study epiretinal membranes in patients with idiopathic macular holes. METHODS: We studied 67 eyes (60 consecutive patients) with idiopathic macular holes. We evaluated the thickness and the extent of the epiretinal membrane by using a scanning laser ophthalmoscope, We then compared the fundus images obtained with the scanning laser ophthalmoscope with red-free monochromatic fundus photographs. RESULTS: Confocal imaging of the fundus with either argon blue (488 nm) or argon green (514 nm) laser illumination clearly showed the epiretinal membranes. In all eyes, we observed lesions ranging from a patchy glinting light reflex to a dense epiretinal membrane, A well-demarcated dense epiretinal membrane around the macular hole was observed in seven (44%) of 16 eyes with stage 2 macular holes and in 12 (40%) of 30 eyes with stage 3 holes, but in only two (10%) of 21 eyes with stage 4 holes, The prevalence of the dense epiretinal membrane in stage 2 or 3 holes was significantly higher than in stage 4 holes (P = .025 and .024, respectively). CONCLUSIONS: Fundus imaging using the scanning laser ophthalmoscope with argon laser illumination is useful preoperatively to evaluate epiretinal membranes in eyes with idiopathic macular holes.