Antibiotics are used worldwide in human medicine and agriculture. In many cases the use of antibiotics is unnecessary or questionable. Consumption of antibiotics is linked to bacterial resistance. In hospitals, most common resistant bacteria include methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci and Gram-negative rods including Enterobacteriaceae and Pseudomonas aeruginosa. Vancomycin intermediate and resistant S. aureus, described just recently, represent a new treatment challenge. In the community, penicillin and macrolide-resistant pneumococci developed several decades ago and are now present all over the world. More recently, community-acquired methicillin-resistant S. aureus has become a problem in several countries causing skin infections but also severe diseases. Resistance to co-trimoxazole in Escherichia coli has changed empirical treatment of urinary tract infections, one of the most common causes of the visit to the physician's office. Several reports and studies trying to limit the use of antibiotics have shown that antimicrobial resistance of bacteria can be reversed, but in general the problem is far from being solved. World Health Assembly and the European Community Council have recognized the problem of antibiotic resistance as a priority. The relationship between agricultural use of antimicrobials and antibacterial resistance in humans should be further investigated.