Triggering receptor expressed on myeloid cells-1 (TREM-1), a member of the immunoglobulin superfamily, plays a crucial role in amplifying inflammatory responses, thereby contributing to the pathogenesis and progression of various inflammatory diseases. This review presents a comprehensive analysis of the current understanding of TREM-1 signaling and its dysregulation in disease pathology. Additionally, it explores the prognostic significance of TREM-1 across a spectrum of conditions. Targeting TREM-1 signaling represents a promising therapeutic approach for managing a wide range of diseases, including cancer, neurodegenerative disorders, cardiovascular diseases, and other inflammation-driven conditions. Previous reviews on TREM-1 have largely focused on its immunological role across diverse disease conditions and selective peptide-based inhibitors targeting its signaling pathway. However, recent discoveries have identified small-molecule modulators of TREM-1 that offer new opportunities for therapeutic intervention. Incorporating these findings would provide a more comprehensive and updated perspective on TREM-1 biology, particularly regarding its molecular regulation, drug-target potential, and translational relevance in inflammatory and immune-mediated disorders. Advances in this field are expected to be driven by structure-based drug design, particularly in the development of TREM-1 inhibitors. However, further research is needed to elucidate the predictive value of TREM-1 alterations and to evaluate them in prospective human studies prior to clinical decision-making.