Recent data suggest that latency of neuroleptic response may be used to separate distinct subtypes of psychotic disorders. In this preliminary study we contrast family patterns of illness of rapid neuroleptic response psychotics and delayed neuroleptic response psychotics. The data show that first-degree relatives of delayed neuroleptic response psychotics evidence higher levels of psychiatric disorder than rapid responders: relatives of delayed neuroleptic response psychotics evidenced a morbid risk for schizophrenic-spectrum disorder that was more than twice as high as the morbid risk for such disorders among relatives of rapid neuroleptic response psychotics. Relatives of delayed neuroleptic responders that received a diagnosis of schizophrenia, schizoaffective, or schizophreniform disorder evidenced significantly more residual impairment than schizophrenic-spectrum relatives of rapid neuroleptic responders. These preliminary data indicate the possibility that latency of therapeutic response to neuroleptic medication may be used to discriminate two familially distinct psychotic disorders and they suggest that delayed neuroleptic response may characterize a familially transmitted poor-outcome disease.