Second language (L2) writing, a cognitively demanding process, has also been perceived to encompass emotional aspects for L2 writers, as they tend to exhibit various feelings toward teacher feedback on their writing performance. Therefore, the current study explored English as a Foreign Language (EFL) Vietnamese students' emotions toward teacher-written feedback and how their emotions were perceived to impact their engagement and writing performance during the writing process. Data was obtained through semi-structured interviews with the involvement of Vietnamese college students after their essays and teacher feedback were collected. The results showed variations in students' emotions were found at different rounds of teacher-written feedback, which the students perceived to influence their cognitive resources, motivation, and self-regulation of learning. Pedagogical implications are discussed, focusing on providing or modifying teacher-written feedback at different stages of the writing process to sustain and promote student engagement with teacher feedback and their writing practice.