A series of novel 3-cyclohexyl-2-substituted hydrazino-quinazolin-4(3H)-ones were synthesized by reacting the amino group of 3-cyclohexyl-2-hydrazino quinazolin-4(3H)-one with a variety of aldehydes and ketones. The starting material, 3-cyclohexyl-2-hydrazino quinazolin-4(3H)-one, was synthesized from cyclohexyl amine. Title compounds were investigated for analgesic, anti-inflammatory and ulcerogenic behavior. The compound 3-cyclohexyl-2-(1-methylbutylidene-hydrazino)-3H-quinazolin-4-one (4c) emerged as the most active compound of the series and is moderately more potent in its analgesic and anti-inflammatory activities compared to the reference standard diclofenac sodium. Interestingly, test compounds showed only mild ulcerogenic potential when compared to acetylsalicylic acid.