Purpose ' This study seeks to examine antecedents of perception of trust as a foundation for extra-role behaviour in the public sector non-profit organisations. Design/methodology/approach ' A total of 1,600 questionnaires were distributed and 329 questionnaires were returned from five different non-profit local government authorities in Australia. Findings ' It was found that perceptions of trust in management, psychological support, management values and rewards were strong antecedents of employee perceptions, which in turn were positively correlated with employee extra-role behaviour. Employee participation in decision making and contributions from autonomous employees were strong indicators of extra-role behaviour, whereas intrinsic job motivation and the sharing of knowledge were found to be weaker indicators of discretionary extra-role behaviour. Research limitations/implications ' The study was based on the voluntary response of employees of five independent local government authorities in Australia. Thus findings in other geographical or cultural locations may be significantly different. Beyond the questionnaire findings, the relevance to private non-profit organisations needs to be studied empirically. Practical implications ' The research makes a significant contribution to management of governmental public sector non-profit organisations which face continuous pressure to develop strategies and embrace management practices that ensure organisational effectiveness. Originality value ' The findings highlight the important factors that lead to employee perceptions about trust which can lead to discretionary employee efforts in public sector organisations that have great similarity to non-profit organisations.