We hypothesized that women are more prone to develop coronary dissections during PCI due to potential balloon-oversizing or gender specific plaque and vascular characteristics. To date, a gender related difference in edge dissection has not been systematically studied. The Massachusetts General Hospital Optical Coherence Tomography (MGH OCT) Registry is an international registry of patients undergoing OCT procedures. We identified 206 consecutive patients (159 men, 47 women) with stable or unstable coronary syndromes demonstrating adequate OCT images for gender specific comparison in areas of non-overlapping stents. Presence of proximal edge dissection, its characteristics, plaque composition at stent borders and luminal diameters were assessed. A multivariate logistic regression model was applied to determine if female gender was predictive of proximal coronary dissection after adjusting for clinical, procedural and plaque characteristics. Proximal coronary dissection was significantly more common in women as compared to men (30.6 vs 15.6%, p = 0.02). No gender differences were observed in age, presentation, and stents per patient or plaque characteristics. The characteristics of edge dissections were different in women compared to men with a significant female predisposition to more complex proximal coronary dissection. In multivariable analysis, female gender was not a predictor of coronary dissection; on the other hand, stent oversizing and especially lipid rich plaque at proximal edge were independent predictors of proximal dissection. OCT confirms that female gender is associated with a greater than twofold increased risk of developing proximal coronary edge dissections as compared to men. But, the most potent independent predictor of proximal coronary edge dissection is the presence of a proximal lipid rich plaque.