On the basis of previous studies, the authors tested pefloxacin, a new generation quinolone, for the treatment of Mediterranean spotted fever. Treatment with this drug brought about complete recovery with rapid subsidence of clinical symptoms and normalization of instrumental and laboratory parameters. This antibiotic should therefore be listed as one of the agents suitable for combatting rickettsial infections and its use should be encouraged in view of its easy handling, excellent compliance and the possibility for oral administration.