Foot and mouth disease virus was propagated on BHK21 and purified by polyethylene glycol (PEG) precipitation. The antigenic properties of the virus before and after purification were studied by infectivity, complement fixing activity and protein assay tests. Inactivated FMD vaccines were prepared from the purified antigen and the crude one. The potency of both vaccines was tested in guinea pigs. The results revealed that the process of PEG precipitation of the virus will improve the quality of antigen used in vaccine formulation to produce a good quality FMD vaccine.