The aim of this study was to provide data on the prevalence of serovars of 48 strains of Actinobacillus pleuropneumoniae isolated in Japan from 2006 to 2011, and their antimicrobial resistance profiles (ARPs) by using the disc diffusion method. Of the 48 strains, 10.4% were serovar 1, 60.4% were serovar 2, 14.6% were serovar 5, and 2.1%, 2.1%, 2.1%, and 8.3% were serovars 6, 7, 12, and 15,respectively. We found that 25.0%, 12.5%, 39.6%, 37.5%, 18.8%, and 0% of the strains were resistant to penicillin G, ampicillin, oxytetracycline (OTC), sulfisoxazole, chloramphenicol, and norfloxacin,respectively. The ARPs of each serovar differed, with serovar 1 strains exhibiting multi-antimicrobial resistance to more than three antimicrobials. In contrast, 44.8% of the serovar 2 strains exhibited no resistance, and 34.5% were resistant to only one antimicrobial. All serovar 1, 5, and 15 strains were resistant to OTC, whereas serovar 2 exhibited lower resistance to OTC (6.9%). No significant increase in the prevalence of resistance to these antimicrobials was observed during the last half decade in Japan when compared with published data on the prevalence of resistant strains of A. pleuropneumoniae collected from 1989 to 2005. Regarding the prevalence of serovars, there has been a recent increase in the isolated cases of serovar 15.