The purpose of the study is the evaluation and comparison of the relative incidence of epiretinal membrane in patients undergoing cataract surgery diagnosed with biomicroscopy versus those diagnosed with optical coherence tomography imaging (Stratus). This prospective study evaluated 146 eyes of patients referred for cataract surgery. Considering biomicroscopic fundus appearance assessed by two examiners and OCT, the following findings were considered to indicate positivity for epiretinal membranes: biomicroscopic evidence of cellophane macular reflex, biomicroscopic evidence of macular pucker, and OCT thickening of the vitreoretinal interface with or without loss of the foveal depression. Positivity (metamorphopsia) to original Amsler test was also noted. Patient mean age was 72.8 ± 9.1 years. Optical coherence tomography revealed 17 eyes with macular pucker (11.6%) and 21 with cellophane macular reflex (14.4%) and, hence, a total of 38 eyes with epiretinal membrane (26%; confidence interval, 18.9-33.1%). Biomicroscopy evaluation overlooked 14 affected eyes, or 9.6% of the eyes examined. False negatives, that is, eyes affected by epiretinal membrane (cellophane macular reflex or macular pucker) and not detected biomicroscopically were 36.8% (confidence interval, 21.5-52.2.7%) and false positives were 1.9% (confidence interval, 0-4%). Amsler test was positive in 7 (18.4%) of the 38 affected eyes. This study finds that patients undergoing cataract surgery may present with epiretinal membrane that are better detected by optical coherence tomography rather than by biomicroscopy. Optical coherence tomography was more sensitive both for eyes with cellophane macular reflex and for those with macular pucker. The use of this instrument before surgery can therefore be considered.