Although research into- English as a foreign language teaching has been abundant, little has, addressed EFL teachers' conceptions and practices of authentic language input in relation to conceiving second language acquisition (SLA) principles to match with taskbased language teaching. The present study had the aim of filling in this gap. The study had the objective of exploring EFL teachers' conceptions of authentic language input; the teachers' practical innovations of the input and the factors that are affecting the ~1:1plementationo f authentic language input at Sanka Secondary and Preparatory School. The study used a qualitative case study research design. Seven participant teachers· were taken purposively during the research because of the nature of a qualitative study to use purposive sampling. Triangulation of data gathering method was made through semi- 'ructured interview, observation of lesson presentations & lesson plan preparations, and focus group discussion. Data was analyzed and interpreted descriptively; segmenting specific information of respondents, as coding was beyond the level of the researcher. In the end, the study indicated that teachers had gaps of conceptions of authentic language input. This was due to teachers' training courses designation that lacked to include authentic language input as part of contents. It was also found that they attached themselves with practices of teaching Enilish little for }anguage production. Their lack of conceptions and practices were also related to both internal and external factors such as teachers' related factors -their beliefs and student related factors- their low proficiency and lack of interest (internal) and institutional constraints such as the syllabus-based teaching approach ( external). The study suggests that EFL teachers should get opportunities for staff development in relation to authentic language input. They have to also get awareness about authentic language input in education programmes. Moreover, it suggested that EFL teachers should apply the pedagogic skills on teaching English as foreign lang~ncluding the language tasks in the EFL contexts, and the curriculum materials should be authentic.