The study investigated students’ patterns of interaction and their viewpoints toward incorporating peer feedback in L2 writing class, making use of a video stimulated recall (VSR) interview and the compositions. Data were analyzed qualitatively; two groups of six students with mixed English proficiency were analyzed in terms of the language-related episodes (LREs). The participants of the study were 21 undergraduate students, majoring in English in a university in the three southernmost border provinces of Thailand. For data analysis, peer dialogues were recoded, transcribed and coded to identify students’ patterns of interactions in terms of collaborative, expert/novice, dominant/dominant and dominant/passive patterns, based on Storch’s (2002) scheme. Moreover, the findings revealed that the students’ English proficiency level did not influence the LREs and their writing ability. Additionally, students’ writing performance was improved in the identified patterns of the collaborative and expert/novice instances. Specifically, students perceived the writing process, developed affective strategies, reinforced their critical thinking ability and enhanced their social interaction skills. Besides, it encouraged them to become more effectively autonomous learners. Hence, peer feedback should be implemented in L2 writing.