62 chronic schizophrenics, who after a psychotic exacerbation were stabilized again, were randomized on 3 different maintenance dosages of flupentixol-decanoate and observed for 12 months. 15 (24.2%) patients had a relapse independently of the dose. 34 of the 47 patients without relapse had complete documentations of the follow-up. After 3 to 6 months there was an obvious and constant clinical improvement as assessed by various test inventories. The BPRS-scores for psychopathology, negative and positive symptoms improved significantly between 14 to 18%. There was also significant reduction of negative symptoms assessed by SANS (22%) as well in the severity of illness (CGI) and an amelioration of psychosocial functioning (GAS, Strauss-Carpenter). At the end of trial 26.4% of the patients had mild involuntary movements (AIMS), 23.5% were on antiparkinson-medication. It is concluded that there could be an indication for flupentixol-decanoate in the long term maintenance therapy especially of chronic schizophrenics with negative symptoms and problems of compliance under oral medication.