A recent report demonstrated that serum levels of epidermal growth factor (EGF) were significantly decreased in patients with schizophrenia, suggesting that impaired EGF signaling might be associated with the pathophysiology of schizophrenia. Our goal in the present study was to determine whether serum levels of EGF are altered in patients with schizophrenia. We found that serum levels of EGF in drug-naive (n = 15) or medicated patients (n = 25) with schizophrenia did not differ from those of age- and sex-matched normal controls (n = 40). However, we found a significant correlation between serum EGF levels and BPRS scores in the combined groups of patients. Therefore, our results do not support the claim that EGF plays a role in the pathogenesis of schizophrenia, but they suggest that EGF may serve as a state marker, that is, as an index of symptom-linked deficits.