Thirty-one chronic psychotic patients were treated with loxapine succinate, 20 for two years and eleven for one year, in order to evaluate its long-term efficacy and safety. Results presented here indicate that loxapine succinate is an effective treatment for chronic schizophrenia over a period of at least two years. Improvement, which occurred during the first six months of treatment (mostly during the first month), was maintained over the following year and a half. Unwanted effects were most frequent inthe early months of treatment and decreased as the two year trial progressed. No specifically long-term side effects were observed. The most frequent side effects were mild to moderate extrapyramidal signs. Blood pressure decreased and pulse rate increased, while remaining within normal limits, and returned to normal or near normal levels during the second year of treatment. Weight increased steadily during the two years and dropped markedly during the four week post-drug period. No drug-related abnormal laboratory findings were observed. It may be concluded that loxapine succinate is a safe and effective maintenance treatment for chronic schizophrenia.