OBJECTIVE: To investigate the performance of the less affected upper limb in people with stroke, compared to normative values. To examine less affected upper limb function in those whose pre-stroke dominant limb became paretic and those whose pre-stroke non-dominant limb became paretic. DESIGN: Cohort study of chronic stroke survivors (7.2±6.7 years post incident) SETTING: The study was performed at a freestanding academic rehabilitation hospital PARTICIPANTS: Forty chronic stroke survivors with severe hand impairment (Chedoke-McMaster Stroke Assessment rating of 2-3 on Stage of Hand) participated in the study. In 20 participants, the pre-stroke dominant hand (DH) was tested, (non-dominant hand affected by stroke), and in 20 participants the pre-stroke non-dominant hand (NH) was tested, (dominant hand affected by stroke). INTERVENTIONS: Not applicable MAIN OUTCOME MEASURE: Jebsen-Taylor Hand Function Test. Data from stroke survivors were compared with normative age- and gender-matched data from neurologically intact individuals. RESULTS: When combined, DH and NH groups performed significantly worse on fine motor tasks with their nonparetic hand relative to normative data (p0.140). CONCLUSIONS: Stroke survivors with severe impairment of the paretic limb continue to present significant upper extremity impairment in their nominally nonparetic limb even years after stroke. This phenomenon was observed regardless of whether the DH or NH hand was primarily affected. As this group of stroke survivors is especially dependent on the nonparetic limb for performing functional tasks, our results suggest that the nonparetic upper limb should be targeted for rehabilitation.