• In an attempt to begin to establish minimum effective dosage requirements for the maintenance treatment of schizophrenia, we undertook a double-blind comparison of low-dose fluphenazine decanoate (1.25 to 5.0 mg/2 wk) with the standard-dose regimen (12.5 to 50.0 mg/2 wk) in outpatient schizophrenics. For the first 126 patients studied, cumulative relapse rates at one year for the low dose were 56% and for the standard dose 7%, a significant difference. Despite the fact that very little dyskinetic symptomatology developed in the sample as a whole, the low-dose treatment appeared to have a significant advantage in producing fewer early signs of tardive dyskinesia. Severity of relapse and total cumulative dosage were also considered.