This study examined how knowledge of metacognitive strategies and navigation skills mediate the relationship between online reading activities and printed reading assessment (PRA) and electronic reading assessment (ERA) across 19 countries using the PISA (Programme for International Student Assessment) 2009 database. Participants were 34?104 fifteen-year-old students (female: 50.1%). The results showed that information-seeking activity, knowledge of metacognitive strategies and navigations skills positively predicted ERA and PRA. Social reading activities negatively predicted knowledge of metacognitive strategies and PRA but had no effect on ERA and the navigation skills in most countries. Increased information-seeking reading resulted in higher ERA and PRA as demonstrated by navigation skills and knowledge of metacognitive strategies. Gender differences in online reading engagement were not statistically significant in most countries. However, girls performed better in knowledge of metacognitive strategies, navigation skills and PRA but were not significantly better on ERA. Multiple group comparisons of gender indicated that the hypothesized model held for both boys and girls. Besides the infrastructure of information and communications technology as a tool to access the cyber informational space, students should be empowered to use appropriate strategies and navigation skills to achieve their goals. Implications for teaching and learning practices are discussed.