We report four cases of the side effects of minocycline seen during the last two years in our department. There was one case of drug-related lupus and three cases of hypersensitivity reactions, including one eosinophilic pneumopathy with pericarditis, one nephropathy and one severe, pseudo-infectious episode of high fever, rash, lympadenopathy, hepatitis and eosinophilia. Minocycline is a tetracycline agent widely used for acne therapy in France and all over the world. During the last few years, there has been an increasing number of reports concerning systemic adverse reactions to minocycline, with on the one hand auto-immune disorders (lupus, autoimmune hepatitis, vascularitis with ANCA), occurring after a prolonged course of therapy and reported recently in the last few years, and on the other hand, hypersensitivity reactions (eosinophilic pneumopathies, hepatitis, nephropathies, myocarditis, serum sickness or pseudo-infectious reactions), occurring precociously in the course of therapy, and potentially severe. Although these side effects are uncommon in the context of the high number of patients who have been prescribed the drug, the first-line antibiotic therapy in acne must probably be reconsidered.