Rickettsial diseases of man, which are prevalent in all the continents (except Antartica) continue to be a major health problem in tropical and temperate parts of the world. Rickettsioses must be considered in every traveller seeking medical attention soon after returning from endemic areas, since the disease can be associated with significant morbidity. When a definite diagnosis has been made by specific serological tests, prompt antimicrobial therapy is indicated. A tetracycline should be regarded as the drug of choice due to its high efficacy, low toxicity, superior in vitro activity and the possibility of relapse which can follow chloramphenicol therapy.