Recent studies have suggested that cognitive-motor dual-task (DT) training might improve gait performance, locomotion automaticity, balance, and cognition in patients with Parkinson's disease (PD). We aimed to investigate the efficacy of cognitive-cycling DT training in patients with early-stage PD. Participants were scheduled to perform cognitive tasks simultaneously with the cycling training twice per week for eight weeks for a total of 16 sessions during their on-states. Clinical assessments were conducted using the unified Parkinson's disease rating scale (UPDRS), modified Hoehn and Yahr stage, Timed Up and Go (TUG) test, gait and cognitive performances under dual-task paradigm, the new freezing of gait questionnaire, Schwab and England Activities of Daily Living scale, 39-item Parkinson's disease questionnaire, and cognitive performance. Thirteen eligible patients were enrolled in the study. The mean age was 60.64±5.32 years, and the mean disease duration was 7.02±3.23 years. Twelve PD patients completed 16 serial cognitive-cycling sessions for two months. After 16 sessions of training (T2), the UPDRS III scores improved significantly in both the off- and on-states, and TUG were significantly less than those at pretraining (T0). During both the single-task and the DT situations, gait performance and spatial memory cognitive performance significantly improved from T0 to T2. The present study demonstrated that cognitive-cycling DT training improves the motor functions, gait and cognitive performances of PD patients.