This paper reports on a repeated measures study of job insecurity conducted during drastic organisational change in one of Australia's large public transport organisations. In a redundant group (n = 32) and a control group (n = 63), effects of job insecurity and the availability of coping resources on psychological health and withdrawal were examined longitudinally by means of self-report questionnaires. Results indicate that job insecurity is associated with a deterioration of psychological health (i.e. leading to psychological distress and burnout), as well as job and organisational withdrawal. Contrary to expectations, however, neither support from colleagues nor management nor unions seemed to protect job incumbents from the negative effects of job insecurity. Apparently, these three sources of potential support do not have a stress-buffering effect. It was concluded that in order to combat the adverse effects of job insecurity on psychological health and morale, the job stressor itself has to be dealt with, instead of trying to render it less harmful by providing more social support.