Background: Genetic epidemiological studies indicate that genetic factors contribute to a familial aggregation of schizophrenia. The form of inheritance has not been elucidated but most studies have been done in Caucasian populations. Aim: To study the form of inheritance of schizophrenia in an urban population of Santiago, Chile, containing an admixture of Spanish origin individuals with Southamerican aborigines. Subjects and methods: Forty four randomly selected schizophrenic probands, 22 female, aged 28 to 48 years old, were studied. From them, an extensive genealogical reconstitution was performed. Probands and relatives were interviewed using the structured interview CIDI and DSM-III-R check-list. Schizophrenia was diagnosed using DSM-III-R criteria. Complex segregation analysis was done using Pointer program. Results: The hypothesis of a multifactorial inheritance, without the participation of major genes, could not be rejected. Likewise, the major dominant and co-dominant gene forms of transmission could not be rejected. Conclusions: Our results show the participation of a major dominant locus and a multifactorial component in the inheritance of schizophrenia, as has been reported elsewhere.