OBJECTIVES: Measurements of Eastern Cooperative Oncology Group Performance Status (ECOG-PS) are widely used to assess disease progression, determine appropriate treatment and prognosis; however, ECOG-PS over time in routine clinical practice is rarely published. This study examined ECOG-PS in patients with stage III and IV melanoma during 1-year from diagnosis in community oncology clinics. METHODS: Electronic medical records from 47 oncology clinics across the US were used for this analysis.  Patients who had melanoma diagnosis, stage information, and ECOG-PS scores were included. Patient clinical, demographic, and treatment characteristics were described. ECOG-PS at diagnosis of stage III and IV melanoma and at every three months were analyzed. Mixed model analysis was undertaken to examine changes in ECOG-PS over time. RESULTS: A total of 266 patients (102 stage III and 164 stage IV) were included in this study. At baseline, stage IV patients had significantly worse mean ECOG-PS scores than stage III patients (0.79 versus 0.35, p=0.001). In patients with both baseline and at least one post-diagnosis assessment (84 and 110 patients with stage III and IV, respectively), mixed model estimated mean ECOG-PS scores changed from 0.69 at baseline to 1.14 at 1-year for stage IV patients and were relatively stable for stage III patients (0.47 (baseline) and 0.54 (1-year)). There were 25 stage III and 43 stage IV patients who received drug treatments for melanoma. The majority of stage III patients (84%) received Interferon only; while 44.2% of stage IV patients received carboplatin+paclitaxel, 32.6% dacarbazine, and 11.6 % cisplatin. Among drug treated patients with stage IV, worsening ECOG-PS over time (from 0.87 at baseline to 1.14 at one year) was observed. CONCLUSIONS:  In patients with advanced melanoma treated in community oncology practices, worse ECOG-PS scores and faster deterioration were observed for patients diagnosed with stage IV compared to stage III. Even in patients treated with systemic therapies, worsening ECOG-PS was also observed over time.