Background: Parkinson’s disease (PD) is the second common neurodegenerative disease and still the pharmacological treatment facing many problemsas motor complication and ineffectiveness of this treatment for most of the nonmotor symptoms. Non invasive brain stimulation (NIBS) as a new adjunctive method for treating these problems, repetitive transcranial magnetic stimulation one of NIBS techniques used in previous studies but with less consistent resultsconcerning therapeutic effect on cognitivs symptoms of PD. Aim of the work: determine whether HF-rTMS targeting LtDLPFC has beneficial effect on cognitive functions of PD patients, and if this effect present could last for longer periods after one month follow up. Patients and Methods: this randomized single blind case-control clinical study included sixty patients with idiopathic parkinson’s disease (PD) from neurology clinic of Ain Shams University hospitals in Cairo, in the period between December 2014 till December 2018. Subjects were classified according to UKPD Society Brain BankClinical Diagnostic Criteria into active and sham groups. Both groups are assessed before, immediately after completing 6 sessions of rTMS and 4 weeks after the last session. Results: This study showed moderate significant improvement ofcognitive symptoms in PD patients of active group compared to Sham group, this improvement limited to the immediately after rTMS phase not maintained in the follow up. Correlations of improvement were minimal between T2 time scores of different scales. Conclusion: HF rTMS applied over left DLPFC showed short term immediate improvement of cognitive functions of PD patients but had no long lasting effects.