Abstract: Objective: To examine the efficacy of Three-dimensional conformal radiotherapy plus whole brain irradiation for treatment on brain metastases from non-small cell lung carcinoma and to evaluate factors affecting the survivals. Methods: The data of 87 patients during Dec 1997 to Dec 2004 were retrospectively reviewed. All were treated with three-dimensional conformal radiotherapy plus upfront whole brain irradiation for brain metastases from non-small cell lung carcinoma. Kaplan-Meier method was used to analyze the survival rate and local control rate, multivariate analysis was performed to determine significant prognostic factors influencing the survivals using the Cox regression proportional hazards model. Results: The overall median actuarial survival was 14 months from the diagnosis of brain metastases. The actuarial survival rate for 12 and 24 months was 53% and 20% respectively. The actuarial local control rate for 6 months and 12 months was 99% and 93% respectively. In multivariate analyses, factors significantly affecting the local control included those as follows: active extracranial disease (P=0.006), brain metastasis numbers(P=0.035) and time from lung cancer diagnosis to the development of brain metastasis (P=0.040). Conclusion: Three-dimensional conformal radiotherapy plus upfront whole brain irradiation provide an effective tool for brain metastases from non-small cell lung carcinoma with tolerable toxicity.