Background: Flatworm infections are among the most common type of infections occurring mostly in underdeveloped and developing countries resulting in malnutrition and deaths is some cases.

Aim: This study was carried in order to determine the type of flatworms often associated with cows slaughtered in Bali abattoirs with a view to knowing their prevalence rate.

Method: Collection of samples took place in the morning hours from 6:30 am-7 am daily during the sampling periods from January 2017 to December 2017. A total number of 140 samples were analyzed by ultracentrifugation, staining and microscopy techniques.

Results: The infection rate was found to be higher in male cows than in female cows. The results further showed that flatworm infestation in the infected cows was as a result of poor water, improper livestock management, and contamination of the cow's food with cyst of helminthes. Fasciola hepatica infestation was highly prevalence when compared with Taenia saginata with the lowest percentage prevalence rate.

Conclusion: The study therefore, showed that Fasciola hepatica and Taenia saginata were the only dominant in male cows with 72 % prevalence rate while the female cows have the least prevalence rate of F. hepat ica and T. saginata infections. In all, Fasciola hepatica had the highest incidence rate leading to fasciolliasis in the cows and in some cases human.