Perspective taking, one's knowledge of their own mental and emotional states and inferences about others' mental and emotional states, is an important skill for writing development. In the present study, we examined how perspective taking is expressed in writing and how it is related to overall writing quality. We analyzed seventh graders' source-based analytical essays (N=195) to investigate (1) the extent to which students incorporated perspective taking in their essays, (2) how the extent of perspective taking in essays differ by students' sex and English learner status, and (3) the extent to which perspective taking in writing is associated with overall writing quality. Findings revealed that students wrote more from their own perspective than that of others. Moreover, the results of multi-level analyses suggested that female students exhibited more varied perspectives but there was no meaningful difference by English learner status. Lastly, greater extent of perspective taking, particularly that of higher level of perspectives (i.e., dual perspective), was associated with better writing quality, after accounting for students' demographic backgrounds (e.g., sex, poverty status, English learner status) and essay length. These results underscore the importance of writing from multiple perspectives on writing quality. [This is the online version of an article published in "Reading and Writing."]