Current research on social media emphasizes that sharing information comes with great benefits to the individual who shares. In this paper, we adopt a different perspective by arguing that individuals with a high inclination to share information through social media also incur substantial cognitive costs. In particular, we hypothesize that during two phases of the sharing process, information appraisal and asynchronous interactivity, the sharer is confronted with information processing requirements that con-siderably draw on his or her limited cognitive capacity and thus increase the likelihood of experiencing information overload. We furthermore argue that this effect is more pronounced for individuals with a high compared to low need for cognition because they feel particularly motivated to process infor-mation. Our hypotheses are supported by a large survey-generated dataset (n=30,392) from six coun-tries. We additionally find a positive direct effect of need for cognition on information overload. We discuss contributions to conversations on information sharing, information overload, and need for cog-nition research in the context of social media and we highlight managerial implications of our findings.