Research over several decades has showed that current operational diagnoses are unlikely to map directly onto the biological substrates of schizophrenia. This has led to increased interest in identifying endophenotypic markers that may provide an intermediate link to underlying genes. This talk will review some of the more promising biobehavioural markers currently being investigated, such as P50 sensory gating, reduced mismatch negativity amplitude and regionally specific gray matter volume loss, and highlight some of the challenges that still remain to be overcome. These include the potential impact of various potential confounds (eg treatment effects and comorbidity). Our current state of knowledge highlights the need for large-scale collaborative efforts that could provide convincing evidence for the utility of putative biobehavioural markers in furthering our understanding of the etiology of schizophrenia.