Background Cancer patients are associated with an elevated risk of suicide. This study aims to investigate the suicide rates and identify risk factors for suicide among patients with malignant intracranial tumors (MITs). Methods Patients diagnosed with MITs during the years of 1975-2015 were identified from the Surveillance, Epidemiology, and End Results (SEER) program. Suicide rates and standardized mortality ratios (SMR) were calculated. Cox regression analyses were used to identified risk factors for suicide among MIT patients. Results Among 115,668 patients with MITs collected from the SEER program, 99 committed suicide. The rate of suicide was 23.02 per 100,000 person-years, and SMR of suicide was 1.90. Diagnosis in recent era (years 2000-2015, SMR = 2.01), male gender (SMR = 1.78), older age (60-79 years, SMR = 3.54), white race (SMR = 1.86), married persons (SMR = 2.31), living in rural areas (SMR = 2.50), history of other malignancy (SMR = 3.81), diagnosis of glioblastoma (SMR = 4.05) and supratentorial location (SMR = 2.45) were associated with an increased incidence of suicide. In addition, the risk of suicide increased significantly within the first year after diagnosis (SMR = 13.04). Multivariate Cox regressions showed that older age, male sex, and supratentorial location were independent risk factors for suicide. Conclusions The suicide mortality among patients with MITs steadily elevated in the past decades. Male sex, older age, and supratentorial location were significantly associated with risk of suicide, especially within the first year following diagnosis. Healthcare providers should early identify and effectively intervene with MIT patients at risk.