A　multimodal　exercise　training　program　might　be　the　best　way　to　improve　motor　and　cognitive　function　in　patients　with　Parkinson＇s　disease　(PD),　but　this　has　yet　to　be　fully　proven　in　PD　patients　with　mild　cognitive　impairment　(MCI).　This　study　aims　to　examine　the　feasibility　and　effectiveness　of　a　theory-based,　multi-component　exercise　intervention　in　older　people　with　PD-MCI.　Participants　were　randomized　into　an　intervention　group　(n=23)　and　an　active　control　group　(n=23),　receiving　the　theory-based　multi-component　exercise　intervention　and　Parkinson＇s　health　exercises,　respectively.　All　participants　performed　60-minute　exercise　training　sessions　three　times　a　week　over　a　12-week　period.　The　retention　rate　at　post-intervention　was　95.7%　(42/46)　for　the　entire　cohort.　The　attendance　rates　were　99.6%　in　the　intervention　group　and　99.5%　in　the　control　group.　No　adverse　events　occurred.　The　intervention　group　showed　significantly　greater　improvements　than　the　control　group　in　global　cognitive　function,　executive　function,　physical　motor　function,　balance　and　gait,　depression,　and　quality　of　life.　This　study　indicates　that　the　theory-based　multi-component　exercise　intervention　demonstrates　high　feasibility　in　promoting　exercise　adherence　and　is　an　effective　treatment　option　for　older　adults　with　PD-MCI.