BACKGROUND Tetanus is a major cause of mortality and morbidity in developing countries. Various modalities of treatment to prevent progression of the disease and alter its outcome have been tried. This study was designed to evaluate the role of intrathecal human anti-tetanus immunoglobulin (TIG) in the management of tetanus. METHODS Thirty-six adult patients presenting to an university-affiliated teaching hospital were stratified based on the severity of disease into mild and severe disease, and subsequently randomly allocated to receive either 250 i.u. of TIG intrathecally or a sham procedure mimicking the lumbar puncture. RESULTS In mild tetanus, TIG administration significantly retarded the rate of progression (p = 0.05), reduced the duration of hospital (p = 0.01) and intensive care unit stay (p = 0.05), need for tracheostomies (p = 0.03) and the dose of sedatives required for control of spasms (p = 0.01). In mild tetanus, the mortality rates were 20% and 30% in the treated and control groups, respectively. CONCLUSIONS We suggest that TIG is useful in reducing the morbidity, progression of disease and mortality in patients presenting with mild tetanus.