The occurrence and fate of human and veterinary antibiotics in the environment has become the subject of recent investigations because of the potential health effects brought about by exposure to these emerging contaminants. One of the biggest issues about antibiotic contamination of the environment is the increased emergence of resistant pathogenic bacteria. Other chronic effects and ecological problems linked to pharmaceutical contamination are also getting more and more recognized. The focus of this article is toward the environmental behavior and potential impacts of the most commonly used antibiotics, tetracyclines and sulfonamides, which are used worldwide at large quantities.