Contralateral C7 nerve root transfer has been proven to improve post-stroke spastic arm function. In contrast, prolonged flaccidity is rare, but current methods offer little support for recovery. Shoulder inferior subluxation is common due to flaccidity of the shoulder abductor muscles, which are innervated by the C5 root. Since hemiplegia limits the use of the ipsilateral nerves and muscles for reconstruction, we therefore transferred the contralateral C7 (cC7) root to C5 and C7 (cC7-C5C7) in an attempt to restore voluntary control of the shoulder and distal upper limb. Two patients with prolonged flaccidity for more than one year were recruited. After 18 months of follow-up, the shoulder subluxation was reduced and S2 protective sensory function was restored in both patients. Patient one recovered with M3 shoulder strenght and hand grasp function, and patient two recovered with M3 elbow strength. Flaccid hand transited to severe spastic hand in patient one. In these two cases, cC7-C5C7 surgery could improve function and reduce shoulder subluxation in post-stroke flaccid upper limb. Further anti-spasticity management could be taken to improve hand function if severe spasticity occurs.