A series of 3-phenyl/ethyl-2-thioxo-2,3-dihydrothiazolo[4,5-d]pyrimidin-7-yl urea and thiourea derivatives were designed and synthesized. All the compounds have been evaluated for their antiparkinsonian activity in catalepsy induced by haloperidol in mice. A majority of the compounds exhibited significant antiparkinsonian activity after intraperitoneal administration. The most active compound carries methoxy group at 2-position of the phenyl ring. Some of the potent compounds were selected for biochemical estimations of malondialdehyde, glutathione, superoxide dismutase and glutathione peroxidase from brain homogenate to highlight the neuroprotective properties associated with them. The results obtained in the present study may lead to the development of a suitable approach to the treatment of Parkinson's disease and may be the starting point for the future drug design.