Web-based surveys have received increasing attention given the potential benefits of convenience, low cost, and time saving compared with other survey modes. However, the use of the internet to collect data is restrained by the lack of willingness of people to respond. The objective of this research is to expose the determinants of intention to participate in a web survey. Based on the theory of reasoned action, this research proposes a model encompassing attitude toward a web survey, social norm, moral obligation, trust in the sponsor of a survey, topic involvement, topic sensitivity, and reputation of the sponsor to predict a potential respondent's web survey participation intention. We examine the proposed model using a structural equation modelling procedure. The results indicate that attitude, social norm, moral obligation, reputation of sponsor, and trust in the sponsor exert positive effects on participation intentions in web surveys; attitude mediates the relationship between topic involvement and participation intention. However, topic sensitivity of the web survey has no effect either on attitude or on participation intention.