Haemophilus parasuis is a common commensal of the upper respiratory track of pigs of all ages. Under poorly understood conditions it can cause a severe systemic infection (Glasser’s disease) that is a significant cause of economic loss in the swine industry worldwide. Many genes have been proposed to encode putative factors in H. parasuis, but in most cases their prevalence varies between countries and their role in pathogenesis is not known. The present study is an extension of a previous work where the MLVA type and distribution of 8 putative virulence genes was determined in 94 Haemophilus parasuis isolates (54 from animals with Glasser’s disease or pneumonia, 25 from nasal swabs of healthy pigs in farms without Glasser’s disease, and 15 reference stains with different reported virulence potential). In the current study, seven putative virulence genes: espP2, ompP2, cdtA, cdtB, cdtC, pilF and vapD were evaluated by PCR amplification. All 15 reference stains were positive for these genes except serotype 2, 6, 10, and 11, which were vapD-negative. As well, 41% of diseased and 60% of healthy pig isolates were negative for the vapD gene. The ompP2, cdtA, cdtB, cdtC, pilF genes were detected in all isolates from the diseased pigs and in most of the isolates from healthy animals. The espP2 gene was present in all except one diseased pig isolate. Fragment length heterogeneity was detected in the ompP2 gene with amplicon size ranging between 490 and 510 bp but there was no correlation between size and the source of the isolates nor was there a correlation between any specific gene and MLVA type.