A laboratory study is carried out to study gender differences and gender interaction effects in structured alternating-offer bargaining. In a symmetric environment, where the 50:50 split is the expected sharing norm, we find no gender differences. In asymmetric environments, where there is no clear sharing norm, but one bargaining party is expected to get more than the other (due to empowerment, entitlement and informational asymmetries), we find that men are less likely to reach an agreement, and that when they do, they bargain for longer and obtain a larger share of the pie. When gender differences are compared between symmetric and asymmetric bargaining environments, gender is not an effect-modifying factor.