AFTER THE observations of Wong and Cox1that aureomycin was therapeuticallyeffective in experimental Q fever in the guinea pig, a study of the usefulness of this drug in the treatment of human Q fever was undertaken. Encouraging results in an initial group of 15 patients have been reported.2Since that time a larger group of patients have been treated with aureomycin. The present report summarizes experience with this antibiotic over a period of one year in the treatment of Q fever in the 45 patients comprising these two groups. PLAN OF STUDY Aureomycin-Treated Patients. —In general, patients suspected of having Q fever were brought to our attention by physicians practicing in areas of the state where the disease appears to occur endemically or in epidemic form. With a few exceptions in which the cases chosen appeared as a part of localized outbreaks, the patients did not come to