Tumors of astrocytic lineage are among the most common primary brain neoplasms in people and dogs. Current understanding of the pathogenesis of astrocytic tumors is limited in dogs compared with humans. In dogs, critical biological data concerning the natural history of disease progression, tumor imaging features, and response to therapeutic intervention are lacking. This review outlines the clinical, genetic, immunologic, and histopathologic characteristics of astrocytic tumors in dogs with special focus on comparative neuro-oncology. Common problems associated with the diagnosis of these neoplasms are summarized. Traditional veterinary histologic typing and grading of astrocytic tumors must be updated and supplemented with molecular data so that future studies directed toward therapeutic intervention and outcome can be optimized.