<p>Even though assessment constitutes an essential component of any educational process, pre-service and in-service teachers at large seem to ignore its multiple implications and manifestations. Assessment continues to be regarded mainly as the summative evaluation which informs teachers of students´ success or failure in their learning process based on a numeric scale. This narrowed approach may be due in part to the lack of preparation and training both in teacher education programs and professional development programs. It is the aim of this paper thus to raise awareness of the relevance of Assessment Literacy (henceforth AL) in the field of English language teaching by re-examining some definitions of assessment, reviewing various studies in the area, analysing some models and alternatives for the evaluation and development of AL in English language teaching, and finally, offering conclusions and recommendations for the development of AL among prospective and in-service teachers so that they can better serve the needs of their students and their institutions.</p>