Toxoplasma gondii has frequently been named as one of the most important foodborne pathogens, in terms of its impact on human health. EFSA advised to include serological testing of pigs on T. gondii infections and audits of pig farms on risk factors for T. gondii infection (EFSA, 2011). In order to generate knowledge about the epidemiology and prevalence of T. gondii infections in pig herds we studied the long term seroprevalence on farms, persistence of infection and variation in results between and within farms. Sera which were routinely taken in Dutch pig slaughterhouses in the Netherlands for the serological monitoring of Mycobacterium avium infections in pigs (Hiller 2013) were also tested for anti T. gondii antibodies. Results of 120,666 sera, collected from January 2012 until August 2014, showed an average of 2% serological prevalence in pigs. Pigs from organic farms had a prevalence of 3,6%. Farm prevalence was much higher, ranging from approximately 30% for conventional farms to 90% for organic farms. Pigs delivered to the slaughterhouse during winter months had a higher prevalence than pigs delivered during summer months.It could be concluded that serological monitoring can be very useful in detecting farms infected with T. gondii. A test cut off of 20PP was the most appropriate.