This article discusses a case study on an item writing process that reflects on our practical experience in an item development project. The purpose of the article is to share our lessons from the experience aiming to demystify item writing process. The study investigated three issues that naturally emerged during the project: how item writers use test specifications in their item writing processes, how group dynamics affect the process, and what factors affect individual item writers' item writing processes. The article provides practical implications regarding the design of test specifications, training item writers, and profiling item writers' characteristics.