The main purpose of this study was to assess the effects of doodling on the learning performance of high school female students in Tehran. The design of this research was a pre‐test–post‐test with a control group. A group of 169 junior high school 12–13 year‐old students was chosen for this study. After being taught a section of the Natural Science course, the students were asked to answer questions related to the lessons. After that, their grades were used as the pre‐test scores. The post‐test was carried out after the devised treatment. During ten sessions of the same course and teacher, the students were each given a blank sheet of paper and were asked for doodling if they felt like doing it. After each session, a couple of relevant written questions were asked to evaluate how well students had learned the lessons. The experiment and control group both consisted of 27 randomly selected students; participants in the experiment group were doodlers and those in the control group did not doodle. To evaluate the doodling effect a t‐test analysis was performed. Comparison of the grades showed that the experiment group outperformed the control group significantly.