OBJECTIVE: To conduct a metabolomics analysis in patients with spondyloarthritis (SpA) and compare results with those from healthy controls. The overall goal was to identify small-molecule substances that may have potential pathogenic and diagnostic significance in SpA. METHODS: This was an observational, cross-sectional, single-centre study that included patients with axial (ankylosing spondylitis [AS]), peripheral (psoriatic arthritis [PsA]) and healthy controls. RESULTS: The study included 50 patients with AS, 50 patients with PsA, and 164 controls. When compared with healthy controls, patients with SpA showed significant differences in 35 metabolites, primarily associated with amino acid and lipid metabolism. However, only two differences were found between the AS and PsA cohorts (glucose and glycerol). CONCLUSIONS: Our data suggest that patients with SpA exhibit significant disruptions in amino acid and lipid metabolism. The large number of identified metabolites offers promising opportunities, both for discovering new SpA biomarkers and for gaining a deeper understanding of the pathophysiology of these chronic inflammatory diseases.