In Parkinson’s disease (PD), a recent study (Lunardi et al., 2009) indicated that a reduced ratio between dopamine (DA) and its metabolites features advanced stages.In this pilot study, we collected cerebrospinal fluid (CSF) samples 120min after a challenge dose (200mg levodopa) and used high performance liquid chromatography (HPLC) with electrochemical and fluorescence detection (ALEXYS) to measure DA, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanilic acid (HVA). The cohort was composed of non fluctuating early PD patients, stage 1–2, below 42months disease duration. CSF samples were analyzed only from PD patients manifesting at least 30% amelioration (UPDRS-III). The main goal was to assess whether catecholamine metabolism correlate with subtle disease progression.The DA title (4.68nM/L), as expected, was not correlated to the UPDRS score (R= 0.4). In contrast, the intermediate product DOPAC (and, in part, the end product HVA) were tightly correlated with the degree of the motor impairment and disease duration. The analysis post-hoc, assuming a motor cut-off of 20, depicts two subpopulations: group I, mean UPDRS 13.3 and group II (mean UPDRS 24) showing a ratio DOPAC/DA, respectively, 5:1 vs 15:1.These observations support the notion that DA metabolites titles indeed reflect the neuro-degeneration of the nigrostriatal terminals. The sensitivity of the DOPAC/DA ratio in monitoring slight UPDRS change might be attributed to compensatory processes among surviving dopaminergic neurons or altered endogenous turnover. Either way, it promises to be an useful and not costly biomarkers to validate neuroprotective strategies.