There are increasing concerns about the role of companion animals as reservoirs for zoonotic diseases (ZD). Therefore, knowledge, attitudes and practices of pet owners in Shiraz, southern Iran about ZD were evaluated. Two-hundred pet owners referring to veterinary clinics, completed a structured questionnaire. Mean age of owners was 34 (+/- 12) years, more than half of owners reported they had heard the term "zoonosis", nearly half had some information about ZD, and veterinarians were their main source of information. Two-thirds of re-spondents had history of bite or scratching. Participants had satisfactory knowledge regarding high risk groups for ZD, however, nearly half did not know that scratching by animal is a route for contracting ZD and 92 % thought that animal vaccination could prevent a large number of ZD. More than half said when their pet is apparently healthy, they do not concern about ZD, and almost all agreed that it is the responsibility of veteri-narians to provide sufficient information about ZD for their clients. Routine vaccinations was practiced by 83 % of the owners, and 79 % washed their hands after contact with pet. Using gloves when emptying feces container and annual stool examination were the least common practices. Education was significantly associated with total knowledge (P = 0.007) and practices scores (P = 0.001), hearing the term "zoonoses" (OR= 2.2, P = 0.015) and concern for ZD in apparently healthy animals (OR= 3.1, P = 0.001). Total practices score was also significantly higher in dog owners (P = 0.005). Age and gender did not show significant associations with any item. This study established baseline estimates for knowledge, attitudes and practices of pet owners toward ZD in the region. Educating pet owners about the interconnection between animal and human health, preferably by veterinarians is highly warranted for prevention of ZD.