An improved gas burner for cooking appliances, with an inner central portion (40) defining an inner chamber (52) provided with a central flame ring (72) and with an outer portion (42) concentric with said central portion (40) defining an outer chamber (47) provided with at least one outer flame ring (78), characterised by comprising a pair of first injectors (14) of substantially horizontal axis, symmetrically disposed about a diametrical vertical plane of said burner, said first injectors (14) being associated with respective adjacent venturi conduits (24) with substantially horizontal parallel axes, feeding said outer portion (42) with a gas/primary air mixture to generate said outer flame ring (78), said adjacent conduits (24) being spaced apart to define a space within which a second injector (16) of vertical axis is disposed facing a venturi conduit (50) of vertical axis feeding said inner central portion (40) with a gas/primary air mixture to generate said central flame ring (72).