The present invention provides a method and a diagnostic kit for diagnosing the presence of Parkinson's disease in a human subject. The method includes the steps of: (1) extracting RNA molecules from a blood sample of the human subject to define a test sample; (2) measuring the amount of each RNA molecule having Sequence ID Nos. 1-14 in the test sample; (3) comparing the amount of each of the RNA molecules having Sequence ID Nos. 1-14 to the amount of RNA molecules having Sequence ID Nos. 1-14 present in a control sample to determine how many of the RNA molecules of Sequence ID Nos. 1-14 are present in a significant amount in the test sample greater or less than in the control sample to define a number of biomarkers; and (4) diagnosing the presence of Parkinson's disease in the human subject if the number of biomarkers is equal to or greater than five.