BACKGROUND Leptospirosis is an important cause of mortality and morbidity in Kerala. The present study is conducted to evaluate the association of serum electrolytes, parameters of renal, hepatic and pancreatic function with the severity of leptospirosis. MATERIALS AND METHODS We enrolled 84 participants in our descriptive study with leptospirosis aged 18 years or above with leptospirosis admitted under General Medicine in 2 years. Pre-existing renal, hepatic and respiratory diseases were excluded. The study was approved by Institutional Ethics Committee and written informed consent was obtained from all study participants. Serum electrolytes, liver function tests, renal function tests, serum amylase, serum lipase and creatinine phosphokinase were done in central laboratory and results were analysed using R®. Parameters are expressed as categorical variables and association was determined using Chi-square test and Fischer's exact test and p <0.05 was considered statistically significant. RESULTS Among the participants (n=84), 71% were males, 70% had severe leptospirosis, 72.6% had hyponatremia, 23.8% had hypokalaemia, 40.5% had elevated serum creatinine, 65.5% had elevated blood urea, 56% had elevated serum total bilirubin (T.bil) and 31% had elevated direct bilirubin (D.bil). Aspartate Amino transferase (AST), Alanine Aminotransferase (ALT), Alkaline Phosphatase (ALP) and Creatinine Phosphokinase (CPK) were elevated in 61.9%, 47.6%, 44% and 15.5% participants respectively. 8.3% participants had elevated serum amylase and lipase. Significant association with severity of leptospirosis was observed for serum sodium (p=0.