Considering the time spent at work and the instability of work life, paying attention to employee well-being and its determinants over the long run and during the turbulence of work is a highly relevant. Although the associations between work-related and personal factors and employee well-being have been studied extensively, relatively little is known about the persistence of these associations over a longer period of time and whether the associations remain in the context of organisational restructuring, such as organisational expansion or downsizing, or what can be done within the organisations to manage the change process and employees reactions to it. The overarching aim of this thesis is to shed light on factors which help employees to stay well in an unstable world of work.