Abstract Introduction: Leukemia is the most common childhood cancer, and acute lymphoblastic leukemia (ALL) accounts for 75 to 80% of all such cases in this population. Survival has increased among children and adolescents due to advances in diagnosis and treatment, with a growing emphasis on the need for rehabilitation to improve functionality and quality of life, mitigating the long-term effects of treatment. Objective: To describe the process of compiling and validating an exercise booklet for children and adolescents during and after treatment for acute lymphoblastic leukemia. Methods: Methodological study using the Delphi technique for validation. The panel of experts consisted of seven healthcare professionals and three mothers of children without ALL. The booklet was evaluated using a form containing 15 items scored on a 5-point Likert scale, and by qualitative assessment. The frequency of the expert ratings, percentage agreement and content validity index (CVI) were presented for each item and the instrument as a whole. Analyses were performed in R 3.5.1 software. Results: The booklet containing stretching, aerobics, strength and relaxation exercises was validated in the second round, reaching 100% consensus. When assessed only by the mothers, 93.33% consensus was achieved in a single round. Conclusion: The exercises booklet was validated for use in the population studied.