Sixty children, aged between 2 and 10 years, had boutonneuse fever during the summer months of 1979 and 1980. They presented with fever and a generalised maculopapular rash. The tàche noire could be seen at the site of the tick bite in 38 (63%) of them. The antibody response, assayed nonspecifically, by the Weil-Felix reaction was positive in 52. A singe titre of more than 1:80 or a 4-fold increase between two paired specimens separated by a 7-day interval was considered diagnostic. Maximum titres were reached at the end of the second week of convalescence in 81% of patients. Treatment with oral oxytetracycline was effective in all cases.