The prevalence of asthma in 2,160 schoolchildren from Arab and Jewish rural and urban communities in central Israel, was determined by means of questionnaire. For the purposes of the study, asthmatic children were defined as those suffering from two or more asthmatic episodes which had been diagnosed by their physicians and had necessitated anti-asthmatic therapy. Doubtful cases were classified after personal interviewing and physical examination. The overall prevalence of asthma was 6.38%. In the Arab rural sample, it was 2.86%, significantly lower than the other groups studied: Arab urban 6.63% (P < 0.001), Jewish urban 9.2% and Jewish rural 8.66% (P < 0.001). The relatively low prevalence in the Arab rural sample is in accordance with the rarity of asthma reported from less advanced societies in other countries. The reasoning for the low asthmatic morbidity found in this group is not clear.