In this chapter, we discuss the technical challenges associated to poultry welfare and we show that the guarantee of welfare goes through important modifications of the systems, wich in turn can have strong impacts on the production. Moreover, poultry is a production that involves very large flocks, which means consequences and specifities in housing, transport and slaughter. Two important steps in the poultry production chain have been chosen here to illustrate the welfare implications and the subsequent technical challenges : the housing of laying hens and the stunning process at the slaughterhouse. The welfare implications of poultry transportation are only briefly tackled in the present chapter. Since 1999, EU-directive (1999/74/CE)fixed the minimum standards for laying hens housing (space allowance, litter, nest and perch available). Utilisation of new systems like furnished cages and alternative systems can lead to a better hens welfare, but attention has to be paid to other implications such as man health or egg qualitè and even birds welfare itself (cannibalism, etc.). During the past decades, both welfare and technological concerns around the stunning/killing process have led to the development of new systems, among which the controlled atmosphere stunning is the most significant. The welfare of bird during the stunning/killing process in various gas mixtures is still a matter of debate. The new systems should be aimed to improve both working conditions and bird welfare. This supposes modernisation of slaughter device as well as catching and transportation.