This study aims to investigate the correlation between some virulence factors and biofilm production among Porphyromonas gingivalis associated with periodontitis. One hundred and two sub gingival swabs have been collected from patients suffering from acute and chronic periodontitis admitted to Specialty Dental center in the Holy city of Najaf and specialized clinics in the Faculty of Dentistry of the University of Kufa from both sexes during the period from September 2017 to January 2018. A total of 34 isolates (28.43%) were identified as P. gingivalis by amplification of 16S rRNA using PCR technique. luxS, lux pro and lux down genes were investigated and the results of PCR showed that none of the strains were possess luxS, 3 strains of P. gingivalis were possess lux pro and 2 strains of P. gingivalis were possess lux dwn. Only 10 strains of P. gingivalis were selected for detection of some virulence factors. The results showed that all strains were unable to produce biofilm with variant abilities of bacterial strains for autoaggregation have been observed (decrease in O.D of bacterial growth after 1 hr. of incubation), and one strain gave +ve results for hemagglutination.