In recent years there has been a growing interest in the impact of co-operative union–management relations on firm performance and organizational outcomes such as employee turnover and absenteeism. This paper seeks to identify the factors that affect the development of a co-operative industrial relations climate and analyses the effects of that climate on organizational and union allegiance and on employee attendance behaviour. The data are drawn from a study of a large automotive manufacturer in Australia. The results indicate that a positive union–management relationship is associated with higher levels of work attendance. Moreover, this outcome is consistent with the presence of strong and effective unionism at the workplace.