PURPOSE: Acceptance, persistence, and adherence rates are low for prescribed HMG-CoA reductase inhibitors (statins), despite demonstrated effectiveness for preventing cardiovascular events. Previously reported data from this study suggest that most hypercholesterolemic patients cite fear of side effects as the biggest obstacle to statin acceptance and continuation. Bounded rationality theory and research suggest that people use rules-of-thumb (mental shortcuts) as decision heuristics that simplify and expedite decision making. Heuristics appear to function as “snap-on” decision tools that may be relatively specific to particular situations. The purposes of this study were to analyze transcripts of interviews with hypercholesterolemic patients to 1) identify putative statin decision heuristics, 2) formulate an integrative model of statin decision making, and 3) suggest ways that care providers could use knowledge of decision heuristics to facilitate shared decision making. METHODS: Audiotaped, semi-structured, individual interviews (20) and focus groups (2 groups, 7 members total) with adult patients with hypercholesterolemia to elicit their attitudes, beliefs, and approaches to statin therapy decision making. Some (16) were taking or had taken a statin; 11 had never taken a statin. Qualitative analysis of interview transcripts and recursive discussion of findings identified putative decision heuristics for statin therapy. Decision heuritics were then included in a new eclectic model of decision making. RESULTS: Qualitative analysis identified eight putative statin decision heuristics. Patients disinclined to take statins appeared to use heuristics designated: “Avoid bringing harm on myself”, “Take only natural substances”, “Don't worry about it”, “Don't bother—won't help”, “Avoid things not understood”, and “Disregard doctor's advice.” Patients positively inclined toward taking statins appeared to use heuristics designated: “Act to avoid threat of harm”, “Do what doctor says”, and “Give it a try.” CONCLUSIONS: Many patients appear to use decision heuristics as “snap-on” tools to decide about statin therapy quickly, with little or no consideration of available information. Care providers might improve statin acceptance and persistence by eliciting and discussing patients' preferred decision heuristics. Challenging assumptions underlying certain decision heuristics could potentially alleviate unrealistic or exaggerated patient concerns. Providers attuned to patients' decision heuristics might be able to prompt some patients to use a different heuristic or a more deliberative and shared decision process.