Background: Research with children shows that theory of mind predicts reading comprehension both concurrently and longitudinally, while research with adults shows increased print-exposure relates to theory of mind understanding. However, until now whether reading and theory of mind have a mutually reinforcing relationship in which they promote one another in parallel has not been explored. Therefore, this study aims to explore further the relationship between theory of mind and reading by investigating reading comprehension, print-exposure and theory of mind together. Method: Theory of mind (Reading the Eyes in the Mind test), reading comprehension (subset of the York Adult Assessment Battery-Revised) and print-exposure (Authors Recognition Test) were measured in a sample of U.K. adults (N = 220). Results: Findings showed that theory of mind was significantly related to both reading comprehension and reading print-exposure. Further, mediation analysis showed that this relationship does not operate with theory of mind mediating the relationship between print-exposure and reading comprehension as an indirect effect of print-exposure on reading comprehension through theory of mind was not found after controlling for age, income and education. Conclusions: The findings provide some initial evidence that, at least in adulthood, reading and theory of mind have a mutually reinforcing relationship in which they promote one another in parallel, but this relationship cannot be explained by theory of mind mediating the relationship between print-exposure and reading comprehension.