Cochlosoma anatis (Kotlan) is a flagellated protozoan that has been implicated in turkey enteritis. After sequencing and comparing a portion of the C. anatis 16S gene, species specific primers were previously developed and used for polymerase chain reaction detection of C. anatis DNA from house flies within 6 h after the flies had been collected in the field. In this study, filth flies were collected from six turkey production facilities in Arkansas during and between outbreaks of enteritis to determine the role of flies in the spread of C. anatis during 2002, 2003, and 2004 using C. anatis specific primers. Over the 3-yr-period we found that 181/1996 (9.1%) of the house flies collected from the farms were C. anatis-positive. There was a highly significant fly sex × month of collection interaction (X²  =  9.83, df  =  2, P  =  0.0073) indicating that greater percentages of males than females were found to be C. anatis-positive in August and October, 2002, and May and July in 2004 (X²  =  12.84, df  =  2, P  =  0.0016) during enteritis outbreaks. Cocholosoma anatis-positive house flies were collected inside and outside the turkey facilities establishing that they could potentially move the protozoan parasite to or from adjacent poultry facilities on the same farm or to or from other turkey farms in the area.