Twenty nine patients with Rickettsiosis (Tick born fever, n: 22, Q fever, n: 7) has been treated with fluoroquinolones. These compounds was used alone n: 25 (Pefloxacin, n: 15; Ofloxacin, n: 10) or associated n: 4 (Pefloxacin + Rifampin). The general efficacy was excellent. Common Tick born fever and pulmonary forms of Q fever was fast cured. Severe Tick born fever (neurologic or polyvisceral forms, n: 5) and Q fever with long term hyperthermia, n: 4 cas always cured without complications but the time necessary to obtain apyrexia was often longer (6 cases).