The present mini-review aims to revise the current literature about the impact of the soluble form of triggering receptor expressed on myeloid cells (sTREM-1) in the pathogenesis of periodontal disease. TREM-1 has been identified as an important modulator of the immune response mainly because of its ability to regulate the expression of pro-inflammatory cytokines and chemokines. The soluble form of TREM-1 (sTREM-1) is released during inflammation and can be identified in biological fluids. It has been observed that the expression of sTREM-1 is increased in gingival crevicular fluid, saliva, gingival tissues and serum from patients with periodontal disease when compared to controls. Moreover, Porphyromonas gingivalis, a common pathogen observed in inflamed gingival sites appears to regulate the expression of TREM-1 in monocytes, which might also contribute to the increase in the pro-inflammatory cytokine release, aggravating the periodontitis’ lesion. In conclusion, the expression of sTREM-1 is relevant to the pathogenesis of periodontal disease due to its capacity to upregulate the pro-inflammatory signalling and therefore be associated with tissue destruction. Such inflammatory upregulation seems to be strongly influenced by the periodontal pathogen Porphyromonas gingivalis.