Objective: the present study investigated childhood learning experiences potentially associated with the development of elevated hypochondriacal concerns in a non-clinical young adult sample, and examined the possible mediating roles of anxiety sensitivity (i.e., fear of anxiety-related symptoms) and trait anxiety (i.e., frequency of anxiety symptoms) in explaining these relationships. Method: 197 university students participated in a retrospective assessment of their childhood instrumental (i.e., parental reinforcement) and vicarious (i.e., parental modeling) learning experiences with respect to arousal–reactive (e.g., dizziness) and arousal–non-reactive (e.g., lumps) bodily symptoms, respectively. Childhood learning experiences were assessed using a revised version of the Learning History Questionnaire (LHQ), anxiety sensitivity levels with the Anxiety Sensitivity Index (ASI), trait anxiety levels with the State-Trait Anxiety Inventory-Trait (STAI-T) scale, and degree of hypochondriacal concerns with the Illness Attitudes Scale (IAS)-Total score. Results: consistent with earlier findings [Watt MC, Stewart SH, Cox BJ. A retrospective study of the learning history origins of anxiety sensitivity. Behav Res Ther 1998; 36: 505–525.], elevated anxiety sensitivity levels were associated with increased instrumental and vicarious learning experiences related to both arousal–reactive and arousal–non-reactive bodily symptoms. Similarly, individuals with elevated hypochondriacal concerns also reported both more instrumental and vicarious learning experiences around bodily symptoms than did students with lower levels of such concerns. However, contrary to the hypothesis, the childhood learning experiences related to hypochondriacal concerns were not specific to arousal–non-reactive symptoms, but instead involved parental reinforcement and modeling of bodily symptoms in general (arousal–reactive and –non-reactive symptoms alike). Anxiety sensitivity, but not trait anxiety, partially mediated the relationships between childhood learning experiences and elevated hypochondriacal concerns in young adulthood. Conclusions: elevated anxiety sensitivity appears to be a risk factor for the development of hypochondriasis when learning experiences have involved both arousal–reactive and arousal–non-reactive bodily symptoms.