BACKGROUND: 5-10% of patients with asthma have severe disease. Many patients experience persistent symptoms despite being T2-low. Obesity is associated with increased asthma symptoms. Eicosanoids have well-described roles in the pathophysiology of asthma and may contribute to persistent symptoms in T2-low severe asthma. OBJECTIVE: To examine the relationship between urinary eicosanoids, asthma symptoms, obesity and T2-biomarkers in severe asthma. METHODS: Urine samples were collected during a randomized controlled trial assessing corticosteroid optimization using T2-biomarker directed care at scheduled study visits (n=728) and at exacerbation (n=103). Eicosanoid concentrations were quantified from urine samples using mass-spectrometry. Metabolite concentrations were log ₂-transformed, z-scored and concentrated by pathway to generate 6 pathway scores. Results were stratified by T2-biomarker status (T2-Low: fractional-exhaled nitric-oxide [FeNO]<20ppb AND blood eosinophil count [BEC]<0.15x10 ⁹cells/L) vs T2-high: (FeNO≥20ppb AND BEC≥0.15x10 ⁹cells/L), symptoms (symptom-low: Asthma control Questionnaire-7 (ACQ-7)<1.5)] vs symptom-high [ACQ-7≥1.5]), and obesity. RESULTS: The cysteinyl-leukotriene (CysLT) pathway score was elevated in T2-high versus T2-low participants (P=0.0007), regardless of symptom burden. The isoprostane pathway score was higher in symptom-high versus symptom-low participants, regardless of T2-status (P=0.01). Higher isoprostane (P=0.02) and thromboxane (P=0.04) pathway scores were associated with increased symptoms in T2-low participants. Corticosteroid exposure, obesity and exacerbations were not associated with raised pathway scores (P≥0.05). CONCLUSION: Thromboxane pathway metabolites were elevated in symptom-high/T2-low participants whereas isoprostane pathway metabolites were associated with increased symptoms, regardless of T2-status. These pathways are not affected by CS exposure. Further research is needed to define the role of eicosanoids in T2-low severe asthma using interventions to perturb these pathways.