In this study new 6-substituted-3(2H)-pyridazinone-2-acetyl-2-(p-substituted benzal)hydrazone V derivatives were synthesized as analgesic and anti-inflammatory agents. The structures of compounds were elucidated by spectral and elemental analysis. Compounds Va, Vb and Vc were exhibited more potent analgesic activity than ASA. Also these derivatives demonstrated anti-inflammatory activity as well as standard compound indomethacin. Side effects of the compounds were examined on gastric mucosa. None of the compounds showed gastric ulcerogenic effect compared with reference nonsteroidal anti-inflammatory drugs (NSAIDs). On the basis of available data, the structure-activity relationship of V derivatives was also discussed. (C) 2009 Elsevier Masson SAS. All rights reserved.