The aim of the present study was to determine the effectiveness of combined exercise and nutrition interventions on physical function and quality of life (QOL) in patients with acute leukemia or malignant lymphoma (ML) during inpatient chemotherapy. The study was a randomized controlled trial where patients with acute leukemia or ML who were receiving inpatient chemotherapy and exercise therapy were divided into an intervention group (IG) and a control group (CG). Both groups underwent resistance training and aerobic exercise. The patients in the IG were instructed to take nutritional supplements twice a day. Assessment items were muscle strength (handgrip strength and knee extension strength), 6-min walking test, skeletal muscle mass, QOL, nutritional status, and fatigue. Two-way analysis of variance showed a significant interaction for bilateral handgrip strength and knee extension strength. No significant interactions were found for the other items. The results of the present study showed improved muscle strength in the IG compared to the CG, indicating the effectiveness of combined exercise and nutrition interventions during inpatient chemotherapy in patients with acute leukemia or ML.