Nineteen patients underwent surgical synovectomy and debridement for the clinical diagnosis of stage I posterior tibial tendon (PTT) dysfunction. Stage I PTT dysfunction is characterized by pain and swelling along the medial aspect of the ankle. Fourteen patients (74%) reported complete relief of pain, 3 patients (16%) reported minor pain, and 1 patient (5%) had moderate pain, and 1 (5%) had continued severe pain. Sixteen (84%) of the patients subjectively reported being "much better" and had a return of function of the PTT, as evidenced by their ability to perform a single limb-heel-rise test. Two patients (10%) underwent subtalar arthrodesis for progressive foot deformity and continued pain. Based on these results, surgical release, tenosynovectomy, and debridement are recommended for the treatment of stage I PTT dysfunction.