The large Danish study of over 3m people found a seven-fold greater relative risk of developing schizophrenia if a person already had a diagnosis of OCD, and a six-fold higher risk of a schizophrenia spectrum disorder.
Researchers said the children of parents with OCD also faced a higher risk.
Although the two conditions are considered distinct mental illnesses, researchers said they coexist more commonly than would be expected among the general population and 'may be more similar than currently acknowledged'.
The longitudinal study looked at the medical records of 3m people between 1995 and 2012, during which time 16,231 people developed schizophrenia. Among these affected patients, 447 (2.8%) had a prior diagnosis of OCD.
Similarly, 30,556 people developed a schizophrenia spectrum disorder, of whom 700 (2.3%) had prior OCD.
'Marked need of prevention'
Researchers calculated the relative risk for patients with OCD at 6.9 times higher for schizophrenia and 5.8 times higher for schizophrenia spectrum disorders. The children of parents with OCD had 4.3 and 3.1 times higher risk respectively.
Researchers said: 'Our results might indicate a marked need of prevention in patients with OCD, especially as comorbid OCD seems to implicate negative outcomes of schizophrenia.
'Patients with schizophrenia and comorbid OCD are reported to have an earlier age at onset, more depressive symptoms and suicide attempts, higher hospitalisation and unemployment rates, higher symptom severity, and greater disability.'
They said the conditions probably exist on a common etiological pathway, adding: 'Further research is needed to disentangle which genetic and environmental risk factors are truly common to OCD and schizophrenia or schizophrenia spectrum disorders.'