Background: The prognosis of patients with brain metastases from non-small-cell lung cancer (NSCLC) is poor. However, some reports suggest that patients with brain metastases at the time of initial diagnosis have a more favourable survival than do patients with advanced NSCLC without brain metastases. Methods: In a retrospective cohort of all new lung cancer patients seen at a Canadian tertiary centre between July 2005 and June 2007, we examined survival after a diagnosis of brain metastases for patients with brain metastases at initial diagnosis and patients who developed brain metastases later in their illness. Results: During the 2-year period, 91 of 878 patients (10.4%) developed brain metastases. Median age in this cohort was 64 years. In 45, brain metastases were present at initial diagnosis, and in 46, brain metastases developed later in the course of the illness. Median survival in the entire cohort was 7.8 months. Survival after the diagnosis of brain metastases was similar for patients with brain metastases at diagnosis and later in the illness (4.8 months vs. 3.7 months, p = 0.53). As a result, patients who developed brain metastases later in their illness had a longer overall survival than did patients with brain metastases at diagnosis (9.8 months vs. 4.8 months). Among patients who received chemotherapy, the survival of patients with brain metastases at diagnosis was still poor (6.2 months). Conclusions: Our data show limited survival in patients with brain metastases from NSCLC. Careful patient selection for more aggressive treatment approaches is necessary.