PurposeA couple of decades ago, the negotiated syllabus was introduced as an alternative to the predetermined syllabus. The review of the related studies shows the number of studies on the use of negotiated syllabus in English language teaching is scanty. The main purpose of the study was to explore the advantages/merits of employing negotiated syllabus in general English courses that undergraduate students take.Design/methodology/approachThe authors employed the phenomenology research method to deeply delve into the undergraduate students' perceptions of the advantages of the negotiated syllabus. The phenomenology method is used for investigating human lived experiences through the descriptions given by the people involved in the study. This qualitative research method is mainly used to study fields with little or no knowledge. The authors collected the data through in-depth interviews with the informants (18 students) who were selected through theoretical sampling. The informants were undergraduate students at Allameh Tabataba'i University who were selected through theoretical sampling. The authors listened to the recordings to transcribe the participants' statements and remarks verbatim. Then, we analyzed the interviews thematically through open, axial and selective coding. This study aimed at exploring the participants' perspectives on the advantages of the negotiated Syllabus. The study's main objective was to investigate the advantages/merits of employing negotiated Syllabus in undergraduate students' general English courses.FindingsFindings revealed that employing the negotiated syllabus resulted in many advantages which were reduced into three axial coding: psychological, pedagogical and individual. Generally, the negotiated syllabus reduces the students' anxiety, improves their motivation, affects their language achievement and develops their critical thinking and learner autonomy.Practical implicationsTeachers are recommended to minimize the constraints and use the negotiated syllabus to optimize language learners' motivation and language achievement in teaching English programs.Originality/valueThe impact of the negotiated syllabus on language learners has been investigated through quantitative research methods. However, the language learners' perceptions of the negotiated syllabus have not been well explored qualitatively.