Ecological, climatic and sociocultural changes, have enhanced the number of known zoonoses being over 200 at the present. Transmission of infectious agents from animals to man occurs by direct contact with the animal, o by ingestion, inhalation or inoculation of infectious agent. In the Región Metropolitana 71 percent of houses with children have pets, mainly dogs, and 58 percent of immunosupressed children have pets too. Dog bites can transmit Capnocytophaga sp and Pasteurella sp that colonize their mouse. Cat transmits Bartonella henselae, being the seroprevalence of B. henselae in cats studied in Santiago 86 percent. Toxocara spp are highly prevalent parasites but unnoticed pathogens in our country, in 84,9 percent of ground samples obtained from public squares of the Metropolitan area Toxocara eggs were detected. Toxoplasma gondii, a scarcely symptomatic infection in immunocompetent hosts but highly symptomatic in immunocompromised patients, has a seroprevalence of 25 to 40 percent in Chile. Trichinosis is a sporadic disease, in pigs slaughtered in the Metropolitan area, Trichinella spiralis prevalence is 0,04 percent. Tinea and Salmonelosis are other frequent zoonoses in infancy, their mean epidemiological features and clinical manifestations are presented. Leptospirosis causes sporadic outbreaks in rural zones. To reduce the frequency of zoonoses, the education of pets owners with respect to their animal health, to stimulate a periodic veterinary control, to vaccinate pets on time as reinforcement of sanitary control of meals of animal origin is recommended