This study aimed to determine the expected treatment benefits from the patient's perspective before and after percutaneous transluminal coronary angioplasty (PTCA). Descriptive study. The sample consisted of 60 patients that underwent PTCA in the cardiology department of a university hospital in Bolu province in Turkey. The patients were interviewed one hour before the procedure and a week after discharge from hospital. The proportion of patients that perceived their health as good after the PTCA was two-fold in comparison to before (48.3%, 88.3%) (P < 0.05). The rate of patients taking heart disease seriously decreased by half after PTCA compared to before (40.0%, 83.3%) (P < 0.05). Almost all of the patients had the wrong interpretation of complete recovery from the diseases before and after PTCA (100.0%, 96.7%) (P > 0.05). Expectations of not having chest pain (P > 0.05), not having MI (P > 0.05), not having fear of death (P < 0.05), and not having stress (P > 0.05) were lower after PTCA in comparison to before. The expectation of not having chest pain was higher in women (60.9%, 47.8%) (P > 0.05), in those not having MI (56.1%, 48.8%) (P > 0.05), and in those having chronic diseases (59.0%, 43.6%) (P > 0.05) before PTCA compared with after. The majority of the patients had the wrong interpretation regarding their PTCA expectations, which decreased dramatically after the procedure. Continuing individualized health education programs on angioplasty for patients and their families will be an important way of dealing with patients' inaccurate interpretations.