There is usually a situation of information asymmetry in mobile shopping. According to signaling theory and applying it to a mobile commerce context, the authors propose a model with some cognitive and experiential quality signals from the vendor and the site that can reduce shopper perceived risk and fear of opportunism: vendor reputation, site design, personalized service, and personalized information. However, as some literature states that male and female behaviour is somewhat different, the authors analyze differences and similarities between men and women in those perceptions of signals, risk, and opportunism. The authors collected information from 447 mobile shoppers, and results show some gender differences, which involve implications for managers when segmenting their potential market of mobile shoppers by gender. Women are more sensitive to signals, whereas for men the reduction of risk is key to less perceived opportunism.