Nursing, as a part of health professions, is concerned with human responses to actual, chronic, or potential health problems. Nurses are accountable for observing and assessing chronically ill patient's responses. They need to be culturally sensitive and alert to cultural influences on patient's behavior as part of health assessment. Understanding culture and ethnicity helps nurses improve the quality of nursing care. The aim of this study was to identify the effect of culture on chronically ill patients' health behavior in Alexandria and Port-Said regions. This study was conducted at the outpatient clinics of Alexandria Main University Hospital and General Hospital at Port-Said. The sample consisted of 200 chronically ill adult patients receiving monthly medication since at least six months, one hundred patients from each setting. Data were collected using an interview questionnaire sheet consisting of four parts. Part I included items related to demographic data, Part II included set of questions related to socio-culture and religious beliefs regarding health and illness, Part III included information related to patient's beliefs and practices about health and illness, and Part IV included questions related to cultural factors affecting health practices regarding health and illness. The findings revealed that chronically ill patients in both setting had similar positive health beliefs about health and illnesses. Only minority of chronically ill patients perform health practices and most of patients in both settings used over-the-counter medication and natural folk home remedies and folk medicine.