The study aims to investigate the pedagogical content knowledge of the prospective language teachers in the English Language Teaching Department of Canakkale Onsekiz Mart University. The mixed research method, sequential explanatory research design was used to collect and analyze the data. Quantitative data obtained from 127 prospective teachers via the questionnaire were analyzed using descriptive and inferential statistics. The researchers made use of content analysis in order to analyze the qualitative data obtained from document analysis, observation procedures, and interviews of the three participants. Themes and codes were created from the transcriptions of the qualitative data collection instruments to conduct both within-case and cross-case analyses aiming to explain the quantitative results. Results reveal that prospective teachers of English believe they do not have required knowledge of the language they teach though they see themselves competent in other knowledge domains. Though they believed they would use communicative methods to language teaching, they preferred using grammar translation method while presenting the new vocabulary items. What they believed they could do and what they actually did were also different considering their knowledge on planning lessons, knowledge of their learners, and knowledge on assessment. Last but not least, their knowledge domain was shaped not only by the teaching experience they had during the Community Service Practices Course and the private courses they had given, but also by pre-service teacher education. Bearing these results in mind, some implications for teacher education were provided at the end of the study.