Bacterial agglutination and polyacrylamide gel electrophoresis (PAGE) were methods evaluated for typing strains of Clostridium difficile. A panel of four antisera, obtained by immunizing rabbits with washed whole cells of different strains of C. difficile, produced distinctive patterns of agglutination. Ethylenediaminetetraacetate (EDTA) extracts subjected to PAGE also produced distinctive protein profiles. Excellent correlation between the two methods was observed when geographically distant isolates were typed without knowledge of their clinical origin. Both typing methods should receive further evaluation for their value as tools for epidemiological studies.