A group of 11 schizophrenic patients, initially participating in a preliminary evaluation of pipothiazine palmitate, has been kept continuously on this long-acting depot neuroleptic drug for a mean period of 10 years and 9 months. The average dose per injection is 75 mg with an average interval of 4 weeks. An evaluation of the physical, mental and social state of these patients is reported. It is concluded that the patients collectively had responded much better than could have been forecast at the outset of treatment. The drug was effective at 4-weekly intervals, the incidence of side-effects was low, and there was no evidence of unforeseen biological effects from continuous medication.