Microbiota dysbiosis may affect both the development and progression of colorectal cancer (CRC). Large metagenomic studies have highlighted specific oral bacteria linked to CRC includingPorphyromonas gingivalis. Few studies have however analysed the implications of this bacterium in CRC progression and survival. In this study, we investigated the intestinal presence ofP. gingivalisby qPCR in both faecal and mucosal samples from two different patient cohorts, including patients with precancerous dysplasia or CRC, as well as controls.P. gingivaliswas detected in 2.6-5.3% of CRC patients and significantly different levels ofP. gingivaliswere found in faeces of CRC patients compared to controls (P= 0.028). Furthermore, an association was found between the presence ofP. gingivalisin faeces and tumour tissue (P< 0.001). Our findings further suggested a potential link between mucosalP. gingivalisand tumours of MSI subtype (P= 0.040). Last but not least, patients with faecalP. gingivaliswere found to have a significantly decreased cancer-specific survival (P= 0.040). In conclusion, P. gingivalis could be linked to patients with CRC and to a worse patient prognosis. Further studies are needed to elucidate the role of P. gingivalis in CRC pathogenesis.