Background: While highlighting is one of the most common strategies to enhance reading comprehension, little is known about how highlighting behavior and its relationship with performance varies across cultures. Our purpose was to examine whether the use and the success of highlighting prevalence, quantity, and task relevance vary internationally. Methods: We used data from five digital PIRLS countries and compared the extent to which students from these countries varied in whether they used highlighting, how much they highlighted, and the relevance of their highlights to the task. We then used a hierarchical logistic regression model to test whether these variables predicted response accuracy and whether their effects were moderated by country. Results: We found that countries differed significantly in their propensity to use highlighting, the number of highlighted words, and whether relevant parts of the text were highlighted. However, highlighting item-relevant text was associated with response accuracy only in one of the selected countries. Conclusions: These results suggest that characteristics of one's language or educational system may impact the association between highlighting and reading performance.