This study aims to examine English as a Foreign Language (EFL) learners' perceptions of the factors influencing their in-class willingness to communicate (WTC) in English. Having been selected through criterion sampling method, the participants consisted of 32 undergraduate EFL learners who took the English course at Balikesir University in Balikesir, Turkey. In this study, which employed qualitative research design, the data were collected through semi-structured interviews. The data generated from the interviews were analyzed through qualitative content analysis. The results of the study showed that learners' in-class WTC in English is affected by a variety of factors including classmates, instructional methods, teacher, classroom atmosphere, materials, class size, L2 motivation, fear of being ridiculed, L2 anxiety, fear of making mistakes, topic interest, topic familiarity, shyness, introversion, vocabulary knowledge, pronunciation, practice, self-perceived communication competence and past communication experience. In light of the results, some pedagogical implications were provided and suggestions for further research were given.