Anti-relapse therapy for vivax malaria is impractical in most epidemic situations because of the duration of treatment and poor compliance. If adequate records are kept, it can be given in the post-epidemic period to patients who have been treated with blood schizonticides. Primaquine 0.25-0.5 mg base/kg bw daily doses should be given for 14 days, as there is no evidence that shorter courses are effective. Compliance with radical (anti-relapse) treatment is often poor and the drug should ideally be given under supervision, which is very difficult in epidemic situations. Appropriate health education should be provided to assist malaria control and encourage adherence.