The primary purpose of this study was to determine differences of patients' satisfaction after HACCP/ISO 22000 implementation in hospital food service. The subjects were 466 patients consisting of 191 males, 275 females from different clinics in one of university hospital. The questionnaire of food and food service satisfaction of patients were filled by intern dietician.Before HACCP/ISO 22000 implementation overall score of patients' satisfaction was 74.7, after HACCP/ISO 22000 implementation it was increase to 81.3 p=0.000. As like as this result approximately all of individual scores (organoleptic, menu and service) were increase after HACCP/ISO 22000 implementation p<0.05. HACCP and ISO 22000 implementation is not only for food quality but also improves organoleptic, menu and service specifications and increase overall satisfaction scores of patients.