Problem statement: In a previous study, the exposure of broiler chicke ns to a weak Electromagnetic Field (EMF) reduced the severity of a coccidiosis infection. The birds were infected by gavage into the crop which was not representativ e for the field situation. Approach: The possible anticoccidial activity of EMF was investigated in b roiler chickens with a simulated, commercial coccidiosis infection. There was an uninfected and infected group not receiving further treatment. Another uninfected and infected group were subjecte d to EMF treatment. The infection was induced by adding to the litter a mixture of E. acervulina , E. maxima and E. tenella . EMF treatment lasted for 30 min day -1 ; the field strength within the cages was set to 5 µTesla rms. Results: Infection with Eimeria resulted in a transient reduction of growth perfor mance in the control chickens. Exposure to EMF counteracted the effect of infection on growth performance. EMF treatment had no effect on oocyst shedding. In the infected birds exposed to E MF, the lesion scores related to the three Eimeria species were generally lower than in the infected c ontrols. Due to cross-contamination, the uninfected birds also showed intestinal lesions, the severity being less than in the infected chickens. In the uninfected birds, EMF treatment also had reduced th e severity of the lesions. Conclusion: In this study EMF exposure protected against coccidiosis in broiler chickens. Consequently, EMF was considered as a possible alternative to anticoccidi al drugs.