The time elapsed between the first onset of symptoms and the onset of first hospitalisation was analysed in 355 participants diagnosed with paranoid, simple, hebephrenic and catatonic schizophrenia and shizoaffective disorder. The real onset of the disease was assessed from interviews with reliable relatives and by reviewing medical records in general practices and out-patient psychiatric services. In 184 patients a family history of schizophrenia was identified. A positive family history was found to significantly increase the interval preceding first hospitalisation in all analysed types, except in catatonic schizophrenia. Possible reasons causing this prolongation are discussed, as well as repercussions of the results to studies using age of first hospitalisation as the leading indicator.