This study investigated elementary school children's development of monitoring and control when learning from texts. Second (N = 138) and fourth (N = 164) graders were tested in the middle (T[subscript 1]) and end (T[subscript 2]) of the school year. The study focused on the cross-sectional and longitudinal development of monitoring and control, and aimed to investigate the development of metacognition for two test formats. After reading expository texts, children completed a comprehension test consisting of open-ended and true-false questions. They monitored their test performance by making confidence judgments, and controlled performance by deciding whether to maintain or withdraw their given answers. Overall, monitoring and control accuracy was higher for open-ended questions than for true-false questions. For open-ended questions, results indicated higher metacognitive accuracy for fourth graders than second graders. No such age effects were found for monitoring and control for true-false questions. Longitudinally, children of both age groups improved their monitoring and control accuracy from T[subscript 1] to T[subscript 2], for open-ended and true-false questions. For both test types, improvement mainly occurred for the monitoring and controlling of incorrect, rather than correct answers. Additionally, the results indicated inter-individual stability of performance, but no stability of monitoring and control accuracy over time. The findings indicate that developmental as well as task-related factors affect children's metacognitive accuracy.