Study design: Psychometric Study.Objectives: To assess responsiveness of the Motor Capacities Scale (MCS) in people with tetraplegia who have undergone upper limb reconstructive surgery.Settings: Rehabilitation clinics in France.Methods: The MCS is an arm/hand function test with 31 basic tasks, subdivided into four sub-categories (MCS A, MCS B, MCS C, and MCS D). Data were recorded preoperatively and following full completion of the surgical program. The Functional Independence Measure (FIM) and a ten-point numeric scale related to patients' satisfaction with the overall surgical result were included. Data were analyzed using responsiveness measures-the effect size (ES), the standardized response mean (SRM), and the minimal clinically important difference (MCID).Results: Twenty-seven participants were included. Fourteen patients underwent unilateral surgery and 13 bilateral surgery. ES and SRM were moderate or good (ES/SRM of MCS B = 0.76/0.81, ES/SRM MCS C = 0.68/0.77, and ES/SRM MCS D = 0.77/0.88). For MCS A and FIM, both SRM and ES showed a small degree of responsiveness. For the MCS total score, the ES value indicated a moderate degree of responsiveness while SRM was excellent. Total MCS score, MCS C subscore and MCS D subscore showed significantly higher ES values in the "bilateral surgery" group than in the "unilateral group". The estimation of MCIDs showed low threshold values of MCS scores changes (total score and subscores) beyond which the satisfaction rate is >6.Conclusions: This study provides evidence of acceptable responsiveness of the MCS to changes using the SRM following upper limb reconstruction in patients with tetraplegia.