Mycoplasma suis (formerly known as Eperythrozoon suis) is an epicellular bacterium that affects porcinered blood cells. M. suis infections occur worldwide and are associated with weakness and anemia in sucklingand weaned pigs, and reproductive disorders in sows. The present field report describes the detection of M.suis in anemic piglets originating from a Belgian farrow-to-finish herd. The herd was experiencing increasedpiglet mortality (16%) in the farrowing unit and had a high percentage of repeat breeders (22%). A controlprogram using antimicrobials and hygienic and sanitary measures significantly decreased the number ofclinically anemic piglets and the mortality rate in the farrowing unit. However, it did not have any significantinfluence on the reproductive failure of the farm. The lack of a significant effect on reproductive failure wasprobably due to the circulation of porcine reproductive and respiratory syndrome virus (PRRSV) on thefarm.