The present paper elucidated the issue of foreign language teachers' knowledge base and the influence of teaching experience on their beliefs. A self-report questionnaire was utilised to explore what domains of knowledge language teachers prioritised in planning and delivering instruction, what sources they drew on to gain professional understanding and to compare teachers' views relevant to the length of their experience. The analysis of data revealed quantitative dissimilarities in the assumed sources and knowledge domains, as well as teachers' instructional preferences. The study's findings lend empirical evidence to the influence of experience on teachers' cognitions and yield additional insight into the way language teachers gain their insider knowledge.