The study of buying centers has often focused on the functional areas that participate. One question raised by such an approach is how individuals choose to participate. The paper explores individual perceptual factors that may affect participation choice, and reports the results of a study of potential purchase participants. Findings indicate that perceptions of self-efficacy and extrinsic reward expectancy discriminated between participants and non-participants. The relationship of the factors and relative influence within the buying center was also explored, with risk of not participating predicting the amount of influence in every stage of the decision process. Self-efficacy perceptions and product involvement were also significant predictors of the amount of influence wielded in the buying center in various decision stages.