Background: Gamma-aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the mammalian brain and is a nonproteinogenic amino acid. Doxorubcin (DOX) or adriamycin is one of the most potent chemotherapy drugs for breast cancer. Purpose: This study focused on diminishing the brain injury and neurotoxicity of doxorubicin (DOX) by GABA administration. Methods: Rats were randomly divided into four groups (8 rats each), which were the control group, DOX group (3 mg/kg for 4 weeks, then 2 mg/kg for 2 weeks), GABA group (2 mg/kg for 21 days), and DOX + GABA group (treated as the second and third groups). Neurotoxicity and brain injury were assessed by determining CSF biomarkers, serum inflammatory markers, and histopathological evaluation of the cerebral cortex. Results: DOX treatment significantly increased the levels of all CSF biomarkers (S100B, IL-1β, ubiquitin carboxy-terminal hydrolase L1 (UCH-L1), glial fibrillary acidic protein (GFAP), spectrin breakdown products (SBDP145), and C-C motif chemokine ligand 2 (CCL2) and all inflammatory markers (IL-6, TNF-α, and IFN-γ), causing extensive neutrophilic infiltration and great alteration in the cerebral cortex architecture as evidence of neurotoxicity. The oral administration of GABA significantly reduced the levels of all CSF biomarkers and inflammatory markers and restored the normal architecture of the cerebral cortex, with observed ameliorations in neutrophilic infiltration. Conclusion: GABA administration can ameliorate neurotoxicity and protect the brain against the negative effects of DOX treatment.