This paper examines the pattern and consequences of commitment toorganisation and union amongst union members in a UK National Health Service(NHS) Trust. Those who perceived the industrial relations climate as positive weremore likely to be dually committed to both organisation and union. As anticipated,union commitment predicted union citizenship behaviours and intent to quit the union.However, organisational commitment predicted intent to quit the organisation but notorganisational citizenship behaviour, which was predicted by union commitment.Findings suggest that those with a unilateral commitment to the union are more likelythan the dually committed to engage in citizenship behaviours aimed at helping fellowmembers and colleagues, perhaps because they feel unconstrained by any strongloyalty to the organisation
