Antibiotics are used for systemic and topical skin diseases treatment, taking advantage of their antiseptic, bacteriostatic and also their anti-inflammatory and immunomodulating properties. In case of localized external skin layers infections, a topical treatment is adequate. In case of widespread and deeper infections a systemic treatment is needed. The latter dermatological diseases are mostly treated by beta-lactam antibiotics (penicillins and cefalosporins) macrolides and tetracycline. In topical treatment mostly erythromycin, clindamycin, mupirocyne and fusidic acid are used. Most common bacterial skin diseases, where topical treatment is sufficient are: impetigo contagiosa, folliculitis and erythrasma. Systemic treatment is required in case of: severe staphylococcal and streptococcal infections, sexually transmitted diseases, secondary bacterial infections (i.e. associated to severe AD or lower leg arterial and venous ulceration), acne vulgaris, rosacea and dermatosis with bacterial antigens pathogenesis influence (i.e. psoriasis, guttate parapsoriasis and angitis). Antibiotic resistance is one of the most worrying problems during the treatment; this is why a targeted therapy, with results guarantee, is mostly appropriate.