This article examines factors that predict changes in consumer purchasing decisions of nonprescription medications. Variables corresponding to factors in Andersen's behavioral model are measured, in addition to data regarding characteristics of the 17 pharmacy consultants who provided counseling services. One thousand seven hundred and thirteen consumers in five stores in southern California were provided consultation during a 6-month period, resulting in 25.4% of the patients purchasing a different drug than intended when entering the pharmacy, 1.3% being referred to a physician, and 13.4% not purchasing any over-the-counter medication at all. Logistic regression techniques demonstrated that one enabling variable (availability of generic medications), and four need factors (the discussion of clinical issues, short encounters, cough and cold products, and vitamin products) were significant predictors of the consumer's decision to purchase a different product than intended. Consultant characteristics (introversion, external locus of control) were also important predictors, but opposite the expected direction. Consumers who received information from female consultants were more likely to change their purchasing decisions.