Although men and women bicycle at relatively equal rates in industrialized countries such as the Netherlands, Germany, and Denmark, research has consistently found that in the United States men's total bicycle trips surpass women's by a ratio of at least 2 to 1. Current evidence, though limited, suggests that women are affected to greater or lesser degrees than men by certain factors. The purpose of this study is to provide insight on gender differences with the factors that influence the decision to use a bicycle, with the intent of supporting policy development aimed at increasing bicycle ridership, particularly among women. Bicycle use in six small cities in the western United States is examined to determine how gender interacts with individual factors and social and physical environments to influence bicycle behavior. Analysis of data from an online survey using a binary logistic regression approach shows strong interaction of gender with individual factors such as safety perception and household responsibilities and, to a lesser degree, with social and environmental factors to influence bicycle behavior.