Background: Reading and writing are both fundamental activities for successful learning. However, little is known about the effect of reading comprehension performance on writing, as well as the pedagogical guidelines that can be drawn from this influence. Method: Thus, the purpose of the present investigation was to examine the influence of performance in reading comprehension, distinguishing between poor and proficient readers (N = 105), who were enrolled in four eighth-grade classes between the ages of 12 and 14, on the writing of narrative and expository texts. Results: Results revealed that proficient readers outperformed poor readers on objective measures of text production and informative/expository texts. Additionally, regression models demonstrated that proficient readers relied more on deeper aspects of reading and writing such as inferential skills, whereas poor readers tended to focus on superficial aspects of texts, or what Kintsch referred to as text-base, and appeared to perform better in reading and writing tasks related to narratives compared to information-based, expository texts. Conclusion: These results support the theoretical perspectives of Kintsch's "construction-integration model" and Otero's "regulation model" regarding the relation between reading, writing and mental representations.