Abstract: A method for gas stunning of poultry for slaughter is described, where the poultry arrives at the poultry slaughterhouse in for example in transport crates, where gas stunning of the animals is effected after the animals have been taken out of the transport crates, and where the animals by means of a number of conveyors (18, 20, 24, 32) are conveyed successively through a stunning chamber (8), where the influence of the gas for stunning of the animals is adjusted by reducing or prolonging the conveying time and/or the conveying route of the animals on said conveyors through the stunning chamber (8).