Objective: To investigate neuropsychological and neurophysiological performances using event-related potentials (ERP) on proprioceptive-motor tasks in young adults with probable developmental coordination disorder (pDCD). Methods: Young adults with pDCD and their matched controls performed ankle movement detection tasks under voluntary response (VR) and non-voluntary response (NVR) conditions. Behavioral performances (mean movement detection time, MDTmean; standard deviation, MDTSD) and ERP indices (N1, P3 amplitude and latency) were measured to assess proprioceptive-motor function. Results: Young adults with pDCD exhibited significantly longer MDTmean and MDTSD compared to controls. ERP analysis revealed significantly smaller N1 and P3 amplitudes in the pDCD group during both VR and NVR conditions at frontal and central electrode sites. Correlation analysis showed strong negative relationships between MDTmean and N1 amplitudes, and moderate negative relationships between MDTmean and P3 amplitudes in the VR condition across both groups. Conclusions: The study reveals that proprioceptive-motor deficits in young adults with pDCD are associated with weaker proprioceptive afferent inflow and reduced allocation of neural resources for motor processes in response to proprioceptive stimuli. Significance: This research elucidates the central brain mechanisms underlying proprioceptive-motor deficits in pDCD, potentially informing the development of targeted sensorimotor interventions for this population.  [This manuscript has been accepted for publication in Brain and Cognition.]