One hundred thirty cases of Q fever were seen in the Basque region of Spain between 1981 and 1984. Approximately 40% of these were related to epidemic outbreaks, and the remainder were isolated cases. The large majority of cases occurred in young men and women between 20 and 40 years of age. A seasonal peak coincided with lambing time in the region. Treatment had favorable outcome in each case, and no chronic disease was seen.