Recently, we reported that 1q/19p co-polysomy predicted poor prognosis in oligodendroglial tumors. In this study, we aimed to retrospectively analyze the prognostic significance of 1q/19p polysomy in two large cohorts of astrocytic gliomas classified by the 2007 and 2016 WHO classification of tumors of the central nervous system. 1q/19p polysomy was detected using the FISH method, and factors that correlated with polysomy were analyzed by logistic regression. Survival analysis was used to identify independent prognostic factors correlated with survival. In the WHO2007 astrocytic glioma cohort (N=421), co-polysomy was associated with a younger age, whereas single polysomy was associated with higher tumor grades and a higher Ki-67 index (P<0.05). Co-polysomy predicted longer survival, and single polysomy predicted shorter survival (P<0.05). In multivariate analysis, co-polysomy maintained an independent prognostic impact on survival (P=0.001) after adjustment for age, KPS, grade, removal degree, tumor size, Ki-67 index, and IDH1/2. In the WHO2016 cohort (N=572), we validated the prognostic merit of co-polysomy after adjusting for related factors. In conclusion, 1q/19p co-polysomy added prognostic information in cases of astrocytic glioma and could be used for molecular stratification of this disease.