Objectives: The aim of this study was to examine whether cervical stabilization exercises (CSEs) change the effects of conventional exercises (CEs) in patients with PD. Methods: Twenty-five patients with PD were randomized into two groups. While the experimental group (EG) received CSEs in addition to CEs, the control group (CG) received only CEs. Both programs lasted 8 weeks. Eighteen participants were able to complete the study. The outcomes were the changes in posture, cervical joint position sense (JPS), balance assessment, 10-m walking tests (10MWT), and the Timed Up & Go (TUG) test. Results: At the end of the study, significant improvement was observed in both groups in terms of trunk rotation angle and pelvic asymmetry, the time parameter of TUG, and the 10MWT (p < 0.05). In the EG, greater improvement was detected in the Berg Balance Scale, static posturography, postural alignment, JPS, and the cadence parameter of TUG (p < 0.05). Discussion: CEs and CSEs could improve walking speed and posture in patients with PD, but if CSEs are added to CEs, greater improvements could be achieved in JPS and postural control. (Clinical Trials ID: NCT03854747).