We aimed to provide recommendations on the infusion duration of anthracycline chemotherapy agents in children with cancer. This study also serves as a practice example of the essential steps that need to be taken when using a previously published systematic review to develop a high‐quality clinical practice guideline. Although evidence was scarce and included adult studies, the panel was able (using the Grading of Recommendations Assessment, Development and Evaluation evidence‐to‐decision framework) to recommend in favor of an anthracycline infusion duration of at least 1 hr (strong recommendation, very low to moderate quality of evidence). Recommending a precise optimal prolonged infusion duration was currently not possible.