Cognitive impairment is a frequent and clinically relevant symptom in patients with Parkinson's disease (PD). Given that pharmacological therapy options are limited, non-pharmacological interventions for the prevention and treatment of cognitive impairment in PD patients are attracting increasing interest. This review summarizes the current state of research regarding cognition-based interventions in PD patients. Eleven randomized controlled studies (RCT) were found in a systematic literature search, all of which used cognitive training (CT). These studies and a recently published meta-analysis demonstrate that especially executive and memory functions can be enhanced by CT in PD patients. Future studies examining CT or cognitive stimulation should include large PD samples with well-defined cognitive inclusion criteria so that clear therapy recommendations can be defined for PD patients without cognitive dysfunctions, those with mild cognitive impairment, and those with dementia.