This study meta‐analyzes 32 studies that examined uncertainty's effects on anxiety and information management within a variety of illness contexts (e.g., cancer, sexually transmitted disease, heart disease). Results indicate that the direction and magnitude of uncertainty's effects vary for different information management strategies. Illness uncertainty is strongly, positively associated with anxiety and avoidance. In contrast, the average effect of uncertainty on information seeking is nonsignificant, but the association does vary depending on uncertainty conceptualization and age. Implications for understanding the nature of illness uncertainty and for communicative efforts designed to facilitate uncertainty management in illness contexts are discussed.