In the field of language testing, there is a growing interest regarding pedagogical approaches to problematize and foster teachers' Language Assessment Literacy (LAL). Although relevant LAL research studies report on the contents and teaching methodologies of assessment courses, few report on their entire design, implemen- tation, and evaluation stages. In Language Assessment Literacy for In-Service Teachers: Online Course Planning and Implementation, the author describes and discusses a systematic approach to plan, teach, and evaluate an online language assessment course for English language teachers in the coffee region of Colombia. In particular, the book explores the following LAL issues: • A discussion of LAL and teachers' professional development, with an emphasis on proposed pedagogies for fostering LAL. • An empirical approach to drawing these teachers' LAL, designing the online course and accompanying materials, implementing the course, and evaluating it. • Ideas for teaching assessment to language teachers and assessing their LAL. in online environments. • Numerous tasks for teacher educators to problematize their own courses for teachers' LAL. • Sample data collection instruments and pedagogical materials to elicit and activate teachers' LAL. Throughout the book, the author constantly invites teacher educators to analyze his proposed approach, while highlighting the challenges and implications inher ent in the enterprise of developing online courses to cultivate teachers' LAL. In conclusion, this book offers conceptual, pedagogical, and research insights into LAL pedagogies involving in-service language teachers