Objectives: Crohn's disease (CD) has been reported to have periodontal manifestations. However, data on periodontal parameters and microbiology is rare. Recent studies showed an association of single nucleotide polymorphisms (SNPs) in the NOD2/CARD15 gene with CD. These SNPs are involved in immune response towards bacterial products. Our aim was to investigate the periodontal status of patients with CD taking into account periodontal pathogens and the NOD2 SNPs 8, 12 and 13. Methods: The periodontal status of 147 patients with CD was assessed. Detection of periodontopathic bacteria were established by PCR using 16S rRNA probes. NOD2 genotyping was done with the Taqman assay. Results: Mean clinical attachment level (CAL) was 3.79 ± 1.01 mm and mean probing depth (PD) 3.59 ± 0.79 mm. 89.1% of the patients had at least one site with CAL > 3.5 mm and 32.0 % at least one site with CAL >5.5 mm. There was no significant difference of CAL and PD between the 3 SNPs. A. actinomycetemcomitans was detected in 76.8%, T. forsythensis in 64.6% and C. rectus in 94.6%. Smoking and medication had no influence on CAL, PD and detection of pathogens. Discussion: Our results suggest that CD patients have an increased prevalence but only moderate severity of periodontal disease. Our data do not support a role of NOD2/CARD15 on periodontal status in CD. However, colonization of periodontal pathogens, in particular C. rectus, might be of particular value for periodontal manifestation of CD. Schlagwörter: periodontitis, Crohn's Diseases, NOD2, periodontal pathogens