An exploratory study of emergency department (ED) utilization, comparing Israeli adult Jews and Bedouin Arabs was conducted. The data interpretation derived from the premise that health services utilization reflects not only morbidity patterns but characteristics of both subcultures and the structure of health services. The Bedouins in the study are a Moslem traditional society going through a rapid process of urbanization and modernization, with a relative deficiency in primary health services. Data were collected from the general ED admissions registry. Patients (17 +) who arrived at the ED during the first week of every even month of one calendar year were selected for this study (6815 Jews and 583 Bedouins). The findings indicate that, in general Bedouins use the ED significantly less than Jews. They adjust to the structure of the ED services and use them, more than Jews, as a primary service. Yet, the hospitalization rates of the two populations are similar. In both subcultures the pattern of gender differences changes after the age of 45. The change, however, is in the opposite direction. Differences in ED usage among Bedouin age-sex groups are discussed in terms of changes in social status during a period of socio-cultural transition.