The advances of Internet and social media offer customers nowadays more opportunities to inform their decisions with product information – not only that promoted by the company but also content shared by micro-influencers. This study aims to investigate the impact of online micro-influencers on the customer’s behavioural intentions. A survey was conducted using convenience sampling with customers in Ho Chi Minh City who have bought or intended to buy smartphones upon viewing online product reviews. Data, upon having been collected and screened, included 371 usable responses and were analysed using PLS–SEM. Results show that the customer’s perceptions of opinion leadership of micro-influencers and their parasocial interactions with micro-influencers positively influence the customer’s behavioural intentions (intention to follow the advice and intention to recommend) through message quality. Managerial implications are also discussed in the paper.