Six pigs, which had been previously shipped to Penghu Island for slaughter from Taiwan Island, were found with vesicular lesions in a detention pen of the slaughterhouse. The incident was reported by the prefecture animal disease control competent authority and the sick pigs were immediately destroyed on 12 February 2010 after sampling. Enforced biosecurity measures including movement control, cleaning and disinfection are implemented. Positive results were obtained by the national laboratory by virus isolation, RT-PCR and antigen detection ELISA tests confirming that those pigs were infected with serotype O of foot and mouth disease virus. Tracing back to the farms of origin, movement control as well as epidemiological surveillance were initiated.