Gamma-hydroxybutyrate (GHB) was administered to seven chronic schizophrenic patients in the first double-blind, placebo-replacement trial of this compound. No significant drug effect in this group was obtained. Two patients became nonpsychotic during the drug trial, three got worse and two patients did not respond. The two patients who responded with improvement were augmenters, as measured by average evoked potential (EP), had low platelet MAO activity and high cerebrospinal fluid (CSF) homovanillic acid (HVA). A number of patients developed akathisia and dystonia during the trial, especially after receiving probenecid for lumbar puncture. Further study is warranted, possibly in a selected patient group.