This article reports on a mixed methods study that examined the effect of reference of comparison (self-referential vs. normative) and regulatory focus (promotion-focused vs. prevention-focused) on willingness to communicate (WTC) among learners of English as a foreign language (EFL). One hundred female English learners were randomly assigned to the self-referential, normative, prevention, promotion, and control feedback groups. They received different types of feedback for 15 sessions. The students were tested for their WTC, anxiety and communication competence before and after the intervention. The results of MANOVA and paired samples comparisons indicated that self-referential, normative, and promotion feedback positively improved WTC and communication competence and decreased anxiety. However, prevention feedback decreased WTC and communication competence and increased anxiety. Follow-up interview data indicated that feedback influenced WTC by providing learning checks or affecting learners' self-confidence, reducing anxiety, fostering motivation, and decreasing peer pressure. Finally, it was suggested that teachers should mainly present feedback to emphasize task accomplishments and growth and to inform the students about their progress over time.