We report a prospective phase II study utilizing limited radiotherapy (RT) treatment fields in elderly (greater than or equal to 75 years) patients (pts) with non-small cell lung cancer (NSCLC) in clinical stage IIIA. Sixteen good risk pts with histologically confirmed NSCLC in clinical stage IIIA, age greater than or equal to 75 years (yr) (range 75-83; median age 77) were entered in the study. All pts were treated with Limited RT fields (including T and N1-2 usually with a 1.5 cm, radiographic margin) and received a minimum of 54 Gy (range 54-62 Gy, median 60 Gy, dose/fraction 2 Gy/5 dd a week). All pts have been followed-up for a median time of 3.5 years (range 1.75-6.58). Median survival (MS) was 18 months (range 7-52 months). No acute and/or late significant toxicity was recorded. Univariate analysis showed a better survival in pts receiving a radiation dose greater than or equal to 60 Gy, with an MS of 34 vs 14 months (p=0.017) and in pts with Karnofsky Performance Status greater than or equal to 80, with an MS of 34 vs 12 months (p=0.0O2). There are scarce data available on survival in elderly pts with NSCLC in clinical stage IIIA. Pts submitted to 'standard' RT in unresectable NSCLC have a poor median survival time and 5-year survival rates. The results obtained in our pts encourage us to use 'limited' RT in elderly but the results require a phase III study before definitive recommendations can be made.