Background/Aim: The interval between diagnostic imaging and whole-brain radiotherapy (WBRT) had no significant impact on survival in our previous study of WBRT for brain metastases. Since median survival time was only 2 months, a potentially negative impact by delaying treatment could have been missed. Therefore, we performed an additional analysis of patients surviving at least 4 months following irradiation. Patients and Methods: The interval between diagnosis of brain metastases and WBRT and ten other factors were retrospectively analyzed for survival in 191 patients surviving 4 months or longer following WBRT. Results: On univariate analyses, Eastern Cooperative Oncology Group (ECOG) performance score of 0-1, 1-3 brain metastases and absence of extra-cerebral metastases were significantly associated with longer survival, whereas the interval from diagnostic imaging to WBRT was not. On multivariate analysis, ECOG performance score remained significant, and extra-cerebral metastases showed a trend towards a longer survival. Conclusion: The interval between diagnostic imaging and WBRT didn't have a significant impact on patients surviving 4 months or longer. Depending on the need for symptom relief, WBRT may be postponed for very important reasons such as obtaining a multidisciplinary tumor board decision or definitive histology.