Farrow-to-finish pig farms in Ontario were visited in 1992 and again in 1999 in order to collect antimicrobial use information, along with fecal and feed samples for isolation of E. coli. The data were used to identify temporal changes in drug use and resistance patterns of E. coli from swine feces. Some of the farrow-to-finish farms visited in 1992 had by 1999 gone out of business or changed management styles. The following resistance prevalences were observed in 1992: ampicillin (40%), spectinomycin (39%), streptomycin (55%), sulfisoxazole (50%), and tetracycline (78%); and in 1999: ampicillin (53%), spectinomycin (53%), streptomycin (50%), sulfisoxazole (55%), and tetracycline (92%). The proportion of farms using tetracycline, carbadox, tylosin, penicillin and sulfamethazine increased from 1992-99, while carbadox remained at approximately the same level. Fewer farms used Lincomycin, Salinomycin, and Spectinomycin in 1999.