Previous studies have shown that the rider satisfaction on bus services vary between males and females. As women make a significant number of transit trips in developing countries nowadays, it is crucial to understand their perceptions and satisfactions towards different service aspects of public transit, thus to provide transit agencies with the gender-differentiated policy suggestions. In this study, we use the QualiÔnibus rider satisfaction survey data in two Brazilian cities: Porto Alegre and Fortaleza, to examine the differences between male and female in their ratings of various transit service attributes, and their perceptions of the relative importance of different service attributes on riders’ overall satisfaction, and based on which detect the high priority service attributes to act on for each gender. The random forest method is applied to determine the attribute importance, which captures both the non-linear and asymmetry influences of the service attributes on riders’ overall satisfaction. Our findings show that the gender difference exists in terms of both the importance type and the improvement priority of the attributes. Specifically, women are associated with higher improvement priorities regarding “speed”, “customer service”, “security”, “exposure to noise and pollution” and “customer information” in Porto Alegre, and regarding “access to transport”, “customer information”, “easiness to transfer”, “comfort at integration terminals” and “speed” in Fortaleza. Our findings illustrate the effectiveness of using our methods to distinguish different importance types of service attributes between different genders, which could help the transit agency develop gender-oriented actions regarding service improvements.