Disulfiram is known to cause hepatitis, which is sometimes fatal. The best estimate of the frequency of disulfiram-induced fatal hepatitis is 1 case in 30,000 patients treated/year. Its appears to be more common in patients given disulfiram for the treatment of nickel sensitivity. Frequent blood testing for liver function is probably not necessary, but patients taking disulfiram should be in regular contact with a physician. There are rare reports of psychosis and confusional states in conjunction with disulfiram treatment and peripheral neuropathy and optic neuritis have been reported; these effects are dose-related. Psychiatric complications appear to be more common with the use of disulfiram in India than in Western countries. Of the less serious adverse effects, tiredness, headache and sleepiness are the most common. Deaths from the disulfiram-alcohol (ethanol) interaction have not been reported in recent years, possibly because the dosages used are lower than those used 40 years ago, and patients with cardiac disease are now excluded from treatment. There is no evidence to suggest that disulfiram causes cancer. Of note, there are drug interactions with compounds that utilise the cytochrome P450 enzyme system. Disulfiram can be viewed as a drug with a moderate record of adverse effects. Alcohol dependence, for which it can be a helpful treatment, is associated with a high morbidity and mortality.