['There is insufficient knowledge of infectious risk in patients after splenectomy; minimal data exists specifically for trauma patients. This study evaluated patient knowledge and practices regarding infection risk after traumatic splenectomy. Our hypothesis was that patients with poor knowledge regarding their asplenic state would be less likely to pursue medical care in the event of an illness than those with good knowledge.', 'Non-randomized, cohort study of all posttraumatic splenectomy patients < or =11 years after injury in 2 rural trauma centers. Patients received a validated questionnaire; weighted responses determined knowledge about infection risks and appropriate follow-up actions.', 'Fifty-four percent of patients responded to the questionnaire. Overall, 47% of responders were identified as having adequate knowledge regarding infectious risk, and only 28% would pursue appropriate medical care. Of patients with adequate knowledge, 42% were more likely to pursue appropriate care versus 15% of patients with inadequate knowledge (p = 0.06). Patients with adequate knowledge were more likely to receive an annual influenza vaccine (p = 0.03) and contact their provider with fewer symptoms (p = 0.03). Logistic regression revealed significant interactions between knowledge and presence of comorbidities (p = 0.04). Focusing on patients with poor knowledge and absence of comorbidities, none would engage in appropriate action in the event of illness (p < 0.01). A longer time since injury, >3 years, was associated with a diminished likelihood of appropriate action (p = 0.03). The relationship between knowledge and action was not accounted for by other potential confounders.'] Do time lapse and comorbidities influence patient knowledge and pursuit of medical care after traumatic splenectomy?