Chromogranin A (CgA) levels in cerebrospinal fluid (CSF) have been reported to be significantly reduced in the later stages of Parkinson's disease (PD). There are only limited data regarding its levels in the early stages, so its significance as a potential biomarker in the diagnosis of PD cannot be established. The aim of our study was to establish the level of CgA in a cohort of treatment-naïve patients with early stage PD. Ten patients (4 males, 6 females) and 10 gender- and age-matched controls were examined for CgA levels in the CSF. Control subjects were patients with low-back pain or tension-type headache. The mean CSF CgA level in PD patients was 74.8 (41.9-123.8) μg/l; in the control group it was 143.9 (116-181.3) μg/l. Statistical analysis showed a difference at the significance level P ≤ 0.05. Our pilot study shows that CSF CgA levels are reduced in the early stages of PD. CgA could therefore be a potential biomarker helpful in the diagnosis of PD.