Long polar fimbria (LPF) is one of the few fimbrial adhesins of enterohemorrhagic Escherichia coli (E. coli) O157:H7 associated with colonization on host intestine, and both two types of LPF (including LPF1 and LPF2) play essential roles during the bacterial infection process. Though the fimbriae had been well studied in intestinal pathogenic E. coli strains, new evidences from our research revealed that it might be the key virulence for bovine mastitis pathogenic E. coli (MPEC) as well. This article summarizes the current knowledge on the LPF in E. coli, focusing on its genetic characteristics, prevalence, expression regulation, and adherence mechanism in different pathotypes of E. coli strains.