This paper explores participants’ perceived benefits and costs that influence the quantity and the quality of voluntary participation in knowledge networks in a resources-constrained economy. A conceptual model of perceived benefits and costs of knowledge sharing is designed on the basis of literature. The influence of perceived benefit and cost on perceived quantity and quality of knowledge sharing are assessed on the basis of a survey with 283 participants in a business context within a resource-restrained economy. The results indicate that reputation, reciprocity, and altruism are perceived to benefit quantity of participation, while reciprocity, altruism, and knowledge self-efficacy are perceived to benefit the quality of participation in knowledge networks. Effort and time have a negative impact on both quantity and quality of participation in knowledge sharing.