OBJECTIVES: This study uses conjoint analysis to examine clinical factors that influence the decision to use specific IgE blood testing as a diagnostic procedure for patients suspected of having allergic rhinitis. METHODS: Participants included a random sample of 50 family physicians in Alabama. For the conjoint analysis physicians evaluated 11 patient profiles (repeated measures) containing four clinical factors: symptom severity, symptom length, patient history, and medication use (prescribed antihistamines, nasal spray, over-the-counter medications). Decisions to test or not test were elicited as dichotomous responses. Visual analog scales were used to support study validity. RESULTS: The largest coefficients were obtained for symptom severity (medium = 2.86; high = 5.12) and symptom length (medium = 1.04; high = 1.03) with history and medication use having moderate influence in the decision process. The overall conditional logistic model was significant (Χ2 = 194.8, P <0.001). All physicians sampled valued testing compared to not testing. For older physicians (age > 50) perceived value compared to not testing was significantly higher (P <0.05). CONCLUSIONS: The value of specific IgE testing is strongly linked to how well test results relate to symptoms (severity, length). Family physicians perceive that specific IgE blood testing is valuable to their practice.