The study presents one case from a larger study that investigated how preservice middle school mathematics teachers planned formative assessment and how they enacted planned assessment in a real classroom. The lesson plan prepared by the participant, pre- and post-interviews with her, and observations of her lesson constituted the data of the study. Findings indicated that the participant used most of the formative assessment strategies unintentionally and in a superficial way. She was unaware that peer- and self-assessment were some of the formative assessment strategies. She mostly asked questions with short answers, not engaging students to discuss the lesson content. She also provided mainly procedural feedback on the task and processing of the task levels. She had time management problems which led her to make changes in the planned formative assessment strategies.