Objective Treatment-free interval has been confirmed as a significant prognostic factor in recurrent gynecological cancers. However, treatment-free interval has not been evaluated in previous studies investigating brain metastasis from gynecological malignancies. The aim of the study was to establish a predictive model of survival period after brain metastasis from gynecological cancer. Methods Of a total of 2848 patients with gynecological cancer, patients with brain metastasis were included in the study. Data at the time of brain metastasis diagnosis, which included primary origin, presence of extracranial metastasis, the Eastern Cooperative Oncology Group (ECOG) performance status, the number of brain metastases, brain-metastasis free-interval, treatment-free interval and treatment for brain metastasis were collected. Survival data were analyzed using Kaplan-Meier methods and Cox proportional hazards models. Results Incidences of brain metastasis were 1.7% (47/2848). Median survival period after diagnosis of brain metastasis was 20 weeks (4-5 months). The 6-, 12- and 24-month survival rates after brain metastasis were 44.0%, 22.0% and 16.5%, respectively. Cox regression analysis showed that extracranial metastasis (hazard ratio [HR], 5.2; 95% confidence interval [CI]: 1.04-26.3), ECOG performance status of 3-4 (HR, 3.1; 95% CI: 1.20-7.91), treatment-free interval of <6 months (HR, 3.8; 95% CI: 1.09-13.1), and no anti-cancer treatment for brain metastasis (HR, 3.6; 95% CI: 1.34-9.41) were significantly and independently related to poor survival. Conclusion Treatment-free interval should be assessed in a future study to verify prognostic predictors of brain metastasis from gynecological cancer.