A longitudinal study to assess change in the symptoms of strain following an industrial dispute was carried out in a North of England ambulance service. A cohort of ambulance staff was surveyed over three stages: during the dispute; during the process of reorganizing the service; and during the implementation of a new operating structure. Dependent variables included measure of job satisfaction and mental and physical health. Independent variables included measures of the type A behaviour pattern, locus of control, source of perceived pressure and coping techniques. The results failed to support the main hypothesis as the symptoms of strain measured did not show any reduction after the dispute. Job dissatisfaction increased in the aftermath of the dispute and remained poor during the implementation of change. Symptoms of mental and physical ill-health showed no reduction following the dispute but symptoms of mental ill-health increased as organizational change was implemented. The high level of 'externality' shown by ambulance staff partially accounted for both these increases. It is proposed that the manner in which the aftermath of the dispute and ensuing organizational change were managed gave an increasingly limited scope for influence.