Factors determining prognosis in tetanus have been based mainly on clinical grounds and mortality is high especially in the developing countries. The biochemical changes occurring in tetanus before any form of therapy or sedation, were examined to determine screening parameters for earlier institution of intensive care in high risk patients. The results obtained from a prospective study of 73 patients are presented. The blood sugar and serum transaminases correlated well with the severity of the disease. The serum glutamic oxalate transaminase and blood urea were significantly higher in fatal cases. These findings as well as the clinical criteria utilized in determining the severity of the disease in this study are useful in predicting the outcome of the disease. It is suggested that these simple investigations could serve as screening parameters for instituting early intensive care in tetanus.