Background: The occurrence of Giardia duodenalis in cats is of potential significance from both clinical and public health perspectives. The object of this study was antigenic detection of G. duodenalis in household cats of Ahvaz district, South-West of Iran. Methods: The prevalence of G. duodenalis was determined in fecal samples by two techniques: centrifugation-flotation and a commercial Giardia Antigen Test Kit (immunochromatography assay) in 150 household cats of different ages among referred cases to Veterinary Hospital of Ahvaz University from January 2008 to February 2010. Results: Five out of 150 fecal samples (3.33%) were positive for antigen of G. duodenalis by immunochromatography assay. The prevalence was significantly higher in young cats less than 6 months (15.79%) compared with adult cats 6 months – 3 years (1.37%) (P=0.027) and above 3 years (1.72%) (P=0.044). The infection had more prevalence in diarrheic cats (17.39%) compared with non-diarrheic cats (0.79%) and the difference was significant (P=0.02) as well. The prevalence was higher in male cats (3.41%) than females (3.23%) and in the season of autumn (6.06%), but the difference was not significant between the prevalence of infection relative to host gender and season (P>0.05). Microscopy examinatio
