PurposeThe purpose of this paper is to explore the interactive effects of employee job autonomy and trust on the relationship between psychological contract fulfilment and work behaviour in international non-governmental organisations.Design/methodology/approachData were collected from 279 employees of international non-governmental organisations (INGOs) with over 10 years of working experience in the INGO industry in Ghana. A questionnaire comprising 27 items pertaining to the study constructs was administered. The reliability of the instrument was verified through item analyses. An exploratory factor analysis was conducted to establish the instrument’s construct validity. The study hypotheses were tested and competing models were compared using multiple hierarchical regression.FindingsAll scales were found to have acceptable reliability estimates. A confirmatory factor analysis established that the manifest variables met the required model fit thresholds and that the latter were empirically distinct. This established the scales' construct validity. The results of the multiple hierarchical regression procedures indicated that a significant number of the study hypotheses could be accepted as statistically significant. A number of moderators were also significant. Specifically, psychological contract fulfilment (PCF) was found to have a positive relationship with organisational citizenship behaviour (OCB). The results also showed a positive relationship between job autonomy and in-role employee performance (IRP) and OCB. There was a positive relationship between both the IRP and OCB. Interestingly, employee job autonomy moderated the positive relationship between PCF and OCB.Originality/valueThis research is among the first of its kind to examine the variables of PCF, work behaviour, employee job autonomy and trust towards the organisation among INGO employees in Ghana. Additionally, the study provides a novel lens to understand the underlying interaction mechanisms through which employee job autonomy moderates the positive relationship between PCF and in-role employee performance. To the best of our knowledge, this study will be the first to combine PCF, trust, employee job autonomy, in-role employee performance and organisational citizenship behaviour in one study. This study confirms and extends the work of Turnley et al. (2003) by including trust and employee job autonomy as key constructs in a social exchange relationship, drawing from the social exchange theory.