A serie of pyridazin-3(2H)-ones derivatives were synthesized and characterized by their physical and spectral data. Then the compounds were screened for antioxidant activities, using established systems such as radical scavenging activity (Dpph), Ferric reducing/antioxidant power (Frap), Trolox equivalent antioxidant capacity (Teac) and inhibition of Lipid peroxidation (Lp). All the tested compounds have exhibited a promising antioxidant activity depending on their structures and the chosen radical.