This study investigated the impact of an online peer-review script on students' argumentative peer-review quality and argumentative essay writing. A pre- and post-test experimental design was used with 42 undergraduate students in the field of educational science. Students were randomly divided over 21 dyads and assigned to two conditions (unscripted and scripted peer-review). Students were first asked to write an original argumentative essay about the topic at hand. Then, students in the scripted condition had to review their peer's argumentative essay based on a peer-review script while students in the unscripted condition reviewed their peer's essay without the script. Finally, all students had to revise their original essay based on the comments of their peers. Students in the scripted peer-review condition outperformed students in the unscripted condition in terms of quality of their argumentative peer-review and argumentative essay writing. These results are discussed and implications are provided.