The goal of the present research was to examine the way in which organisational identity orientation and corporate social responsibility (CSR) interact to produce affective attachment and related beneficial behaviours among organisational members. Using a questionnaire administered in Poland, it was shown that when CSR activity was viewed as authentic by employees, it led to affective attachment to the organisation's CSR stance, while an instrumental evaluation was correlated with a negative attachment to the CSR stance. The results suggest that CSR motives were particularly important for organisations with relational and collectivistic identity orientations because of the focus of these organisations on mutual or collective good that could be demonstrated through CSR. The results contributed to social identity literature by establishing a clear relationship between the concepts of identity orientation and CSR and showing that only authentic CSR produces affective attachment and behaviours that benefit the organisation.