The study investigated the influence of perceived organisation support (POS), employee engagement, and organisation citizenship behaviour (OCB) on quality performance of ISO 9001:2000 certified manufacturing firms in Sri Lanka. A random sample of 255 shop-floor employees that fulfilled the selection criteria set for the study responded. Structural equation modelling was used for the data analysis. It was found that OCB-I mediates the relationship between POS and quality performance as well as employee engagement and quality performance. However, the findings suggest that neither POS nor employee engagement operates as an antecedent to OCB that immediately benefit the organisation in general (OCB-O).