Macular pucker, the vitreomacular traction syndrome, and impending macular hole are three idiopathic macular disorders sometimes treated by vitreous surgery. Each condition has distinctive clinical features, pathogenic mechanisms, vitreoretinal anatomy, surgical findings, results, and complications. The clinical and pathologic features of these three conditions are compared based on a series of: (1) 101 idiopathic macular pucker cases for which clinicopathologic correlation with transmission electron microscopy (CPC-EM) was available, (2) 24 cases of the vitreomacular traction syndrome (7 patients with CPC-EM), and (3) 43 cases of impending macular hole (7 patients with CPC-EM). All cases of macular pucker, 16 cases of vitreomacular traction syndrome, and 15 cases of impending macular hole have been reported. The median visual acuity for patients with epiretinal membrane and vitreomacular traction syndrome improved from 20/200 preoperatively to 20/70 and 20/50 postoperatively. Macular holes occurred postoperatively in 11 of 43 patients with impending macular hole. The three conditions must be differentiated clinically so that proper recommendations regarding prognosis and possible surgical management can be made. RETINA 10:288–296, 1990