<h3>Background</h3> Spondyloarthritis (SpA) are a group of interconnected inflammatory arthritides that include ankylosing spondylitis (AS), reactive arthritis (ReA), and undifferentiated SpA (uSpA). Periodontal disease (PD) is a chronic inflammatory disease that may increase the risk for immune diseases like rheumatoid arthritis and AS. <h3>Objectives</h3> To evaluate the periodontal condition and presence of <i>Porphyromona gingivalis</i> (<i>P. gingivalis</i>) and <i>P. gingivalis</i> IgG1 and IgG2 antibodies within three subgroups of SpA (AS, uSpA and ReA) and establish possible associations with disease activity measures. <h3>Methods</h3> A cross-section observational study was designed. Seventy-nine subjects were included (AS: 19, ReA: 14 and uSpA: 46). Clinical evaluation of rheumatologic and periodontal condition was performed. <i>P. gingivalis</i> presence by polymerase chain reaction (PCR) and <i>P. gingivalis</i> IgG1 and IgG2 antibodies as well as erythrocyte sedimentation rate (ESR), high sensitive C reactive protein (hsCRP), rheumatoid factor, cyclic citrullinated peptide antibody (ACPAs), HLA-B27 and disease activity measures were assessed. A descriptive analysis of frequency distributions for clinical, laboratory and demographic data was made. Associations between clinical and microbiological markers of <i>P. gingivalis</i> infection, including IgG1 and IgG2 antibodies, and SpA disease activity measures were evaluated. Chi-squared test was performed to determine associations. Comparisons between groups were made with Kruskal Wallis, Mann-Whitney U and Wilcoxon test. The study was approved by local ethics committee. <h3>Results</h3> Forty-four (55.7%) patients with SpA presented PD, of which uSpA had a higher frequency (65.2%). Most patients had moderate PD (AS: 26.3%, uSpA: 50.0%, ReA: 21.4%). A high frequency of retired uSpA patients (87.5%) had moderate PD (p=0.044). The clinical attachment level (CAL) ≥4mm (8.1 ± 10.5) and % of CAL ≥4mm (5.7 ±7.7) was more frequent in uSpA patients (p=0.033 and p=0.034 respectively). <i>P. gingivalis</i> presence in uSpA patients was associated with the use of sulfasalazine (p=0.017), and in retired patients (p=0.028). In AS patients, positive IgG1 to <i>P gingivalis</i> was associated with % periodontal pocket depth ≥4mm (p=0.04) and % sites with sample pocket depth (SPD) ≥4mm (p=0.02). Also in this subtype, positive IgG2 was associated with bacterial plaque index (p=0.03). Positive levels of IgG2 in uSpA were associated with bleeding of probing (BOP) (p=0.03) and the number of compromised periodontal interproximal sites (p=0.05). See Table 1. <h3>Conclusions</h3> We found a high frequency of PD in patients with SpA without significant statistical differences between each subtype. The differences in clinical periodontal variables in SpA subtypes probably suggest a better oral hygiene in these patients. <i>P. gingivalis</i> IgG antibodies may be a useful tool for the physician to assess periodontal condition in these patients. <h3>Disclosure of Interest</h3> None declared