Background: Leptospirosis is a zoonotic disease withsymptoms ranging from a mild, febrile illness to a severeform with multiorgan failure. Severe leptospirosis mayrequire medical interventions in the form of dialysis and/ormechanical ventilation and often leads to mortality. Anexaggerated host immune response—in particular, a“cytokine storm”—that causes endothelial and organdamage is associated with the disease severity andmortality.Methods: Microscopic agglutination test (MAT)-positive andMAT-negative human serum samples (n=30) from patientswith leptospirosis were obtained from the Public HealthLaboratory, Kota Kinabalu, Sabah, Malaysia and controlserum samples (n=10) were obtained from healthy studentvolunteers. We estimated the levels of IL-1β, IL-6, IL-8, IL-10,and TNF-α in serum samples by a Luminex assay.Results: The levels of IL-6, IL-8, and IL1-β were significantlyhigher in 13% of the patients with leptospirosis compared tothe healthy controls, while the levels of IL-10 and TNF-α werenot elevated in either group.Conclusion: Our data suggest that elevated levels of IL-6, IL-8, and IL1-β may be associated with leptospirosis diseaseseverity, which requires patient follow-up for confirmation.