Lateral ventricle contact (LVC) by glioblastomas has been proposed to reveal their origin and may have prognostic value; however, results from previous studies have been controversial. This study explored the association between LVC and tumor origin and prognosis in glioblastoma patients. Magnetic resonance imaging and clinical data from 115 glioma patients were retrospectively reviewed, and Kaplan-Meier analysis and Cox proportional hazards models were used to assess the occurrence of LVC as a function of survival in 43 glioblastoma patients. The mRNA expression profiles were compared by microarray analysis in LV-contacting and non-LV-contacting glioblastomas (LVCGs and NLVCGs, respectively). The sphere-forming and invasive capabilities of LVCG- and NLVCG-derived stem cells were compared in primary glioma stem cell cultures with tumorsphere formation and Matrigel assays, respectively. LVC was more frequently detected in high-grade gliomas which, along with LVCGs, were significantly larger than low-grade gliomas and NLVCGs. LVC parameters were not independent predictors of glioblastoma patient prognosis; the expression profiles (including stemness genes expression) were similar between LVCGs and NLVCGs, and no significant differences were observed in tumorsphere-forming capacity and invasiveness between stem cells derived from the two glioblastoma types. Our results suggest that the origin of glioblastomas cannot be simply estimated by radiographic LVC, and after standard therapy the prognostic value of LVC needs to be carefully interpreted.