The present study evaluated quinazoline alkylthio derivative (QATD) for possible role in the treatment of vascular dementia (VD) in rat model. The established T-maze test was used for assessment of behavioural changes and Morris water maze (MWM) test for analysis of spatial learning in rats. Light microscopy using Nissl-staining was used to determine the survival of neurons in rat hippocampus and expression of proteins was measured by western blotting. The study demonstrated that QATD treatment of the VD rats significantly (p < 0.05) alleviated the impairment in spontaneously altered behaviours and significantly (p < 0.05) reduced escape latency. VD mediated decrease in distance travelled, swim time and count of platform crossings was significantly (p < 0.02) alleviated by QATD treatment of the rats. Moreover, in QATD treated rats, VD mediated increase in Beclin-1 and Microtubule-associated protein light chain 3II (LC3II) expression in the hippocampus tissues was significantly (p < 0.05) alleviated. In addition, QATD treatment prevented suppression of mammalian target of rapamycin (mTOR) phosphorylation in VD rat hippocampus tissues. However, rapamycin mediated suppression of p-mTOR and elevation of Beclin 1 and LC3II expression in rat hippocampus could not be alleviated by QATD treatment. In summary, QATD effectively prevents VD mediated cognitive impairment and neuronal damage in the rats. Moreover, autophagy was inhibited and the mTOR pathway activated in rats with VD by QATD treatment. Therefore, QATD may be studied further as a therapeutic agent for treatment of dementia.