Social media is increasingly being used worldwide to produce and exchange information. However, the absence of adequate control mechanisms on this medium has led to concerns about the credibility of information in circulation. While this topic has gained researchers’ attention, little is known about the factors which allow individuals to detect fake news and lead them to trust social media as a source of information, and whether this varies across cultures. This cross-cultural study conducted in Spain and Lebanon uses structural equation modelling to explore these factors and presents them within a behavioural model. Findings show that verification behaviour, information skills and education have a positive influence on fake news detection with a stronger impact in Lebanon. Trust is positively affected by virality with higher influence in Lebanon, while ability to detect is shown to decrease trust in Spain. Frequency of use impacts trust equally in both countries.