This work has been carried out to investigate the utility of arylidene acetoacetanilides 3a, b in heterocyclic synthesis. Thus, the synthesis of pyridine derivatives 6a, b, 8a-d, 12a, b were done by the reaction of arylidine derivatives 3a, b with activated methylene groups 4a, b also synthesis of compounds 15, 21a, b, 22a, b were carried out via the reaction of compound 12a with benzaldehyde (2a) and reaction of arylidine derivatives 3a, b with ethylcyanoacetate (4b) in addition to reaction of compound 21a with either benzaldehyde (2a) or salicylaldehyde (2c) respectively. Isoquinoline derivative 14 was afforded via the reaction of compound 12a with malononitrile (4a). Thieno[3,4-c]pyridine derivatives 10, 19 were afforded via the reaction of 2-pyridone derivatives either 8a or 12a with elemental sulphur respectively, pyrazolo[3,4-b]pyridine drivatives 18a, b were synthesized through the reaction of compound 12a with either hydrazine hydrate or phenylhydrazine 16a, b. Finally pyrido[3,4-d]pyridazine derivatives 25a, b were produced via the reaction between compound 21a and aryldiazonium chlorides 23a, b. The biological potentialities of the prepared compounds has been examined and evaluated as antitumor agents. All compounds showed significant growth inhibitory effect