Twelve new 1-(4-substituted-phenyl)-3-(4-oxo-2-methyl-4H-quinazolin-3-yl)-urea were synthesized and screened for anticonvulsant, CNS depressant, and sedativehypnotic activity. After i.p. injection to mice at doses of 30, 100, and 300 mg/kg body weight 2,3-Disubstitutedquinazolin-4(3H)-one were examined in the maximal electroshock-induced seizures (MES) and subcutaneous pentylenetetrazole (scPTZ) induced seizure models in mice. Spectroscopic data and elemental analysis were consistent with the newly synthesized compounds. The neurotoxicity was assessed using the rotorod method. M3, M4, and M10 were found to be active in both MES screen and scPTZ screen at 0.5 h. All except M11 showed more than 44% decrease in locomotor activity after 1 h of compound administration via actophotometer screen. CNS-depressant activity screened with the help of the forced swim method resulted into some potent compounds. Except for M6 and M11 other tested compounds were found to exhibit potent CNS depressants activity as indicated by increased immobility time. It can be concluded that newly synthesized compounds possessed sedative-hypnotic and CNS depressant activities.