Magnetic resonance imaging (MRI) studies have demonstrated differences in the subcortical structure of schizophrenia patients compared to controls; nonetheless, it is not clear whether these changes are reason for or the result of schizophrenia (SZ). We aimed to investigate whether the basal ganglia volume was different in medication- naïve first episode schizophrenia patients. Seventy-one drug-naïve patients with first-episode psychosis (FEP) who applied to outpatient clinics and were diagnosed according to DSM-5 as well as 47 healthy controls (HC) were included in the study (n=118, 64 males, 54 females). T1-weighted images were acquired on a 1.5 T scanner (Magnetom SP, Siemens), and the basal ganglia volume was measured using the VolBrain software. Symptoms were assessed with the Positive and Negative Syndrome Scale (PANSS) by an experienced psychiatrist. The volumes of right (R) and left (L) striatum, R- and L-caudate (CAU), and R- and L- Substantia nigra (SN) were found to be higher in FEP patients compared to the HC. The volume of L-putamen was higher, while that of the L- Globus pallidus (GP) and L-nucleus accumbens (NAcc) was smaller in FEP patients compared to HC. No significant correlation was found between volume measurements and PANSS scores. R-CAU, L-CAU, R-Striatum, L-Striatum, L-Putamen, L-NAcc, R-GP and L-SN were found to significantly predict psychosis in a Univariate Logistic Regression Model. Basal ganglia are affected from the first stage of the disease in schizophrenia, and it can be more possible that these changes are the result of pathogenesis schizophrenia.