Schizophrenia is a complex genetic disorder manifesting combined environmental and genetic causation. Recently, genome-wide association experiments yielded remarkable new experimental evidence that is leading to a better understanding of the genetic models and the biological risk factors involved in schizophrenia. These studies have discovered uncommon copy number variations (mainly deletions) and common single nucleotide polymorphisms with alleles associated with schizophrenia. The aggregate data provide support for polygenic inheritance and for genetic overlap of schizophrenia with autism and with bipolar disorder. It is anticipated that the application of a myriad of tools from systems biology, in combination with biological functional experiments, will lead to a delineation of biological pathways involved in the pathophysiology of schizophrenia, and eventually to new therapies.