Laboratory workers are exposed to a variety of potential occupational health hazards including those deriving from infectious materials and cultures, radiations, toxic and flammable chemicals, as well as mechanical and electrical hazard. Although all of them are significant, this paper will focus on biological hazards present in clinical and research laboratories. In fact, in spite of numerous publications, guidelines and regulations, laboratory workers are still subject to infections acquired in the course of their researches. This paper describes some aspects that include good microbiological practices (GMPs), appropriate containment equipment, practices and operational procedures to minimize workers' risk of injury or illness.