Chemotherapy is associated with an increased risk of ototoxic changes. The purpose of our study was to investigate the clinical usefulness of Distortion Product Otoacoustic Emissions (DPOAEs) as early indicator of chemotherapy-induced ototoxicity. Tonal audiometry, emission audiometry and DPOAEs were measured in 7 children with acute lymphoblastic leukemia (ALL). Measurements were performed before and after each protocol of chemotherapy. Cochlear activity was evaluated by recording 2f1-f2 DPOAEs with L1=65 and L2=60 dB SPL. Comparisons of the DP-grams amplitudes were performed between baseline measurements and those recorded before and after each chemotherapy course. Our results indicate that DPOAEs measurements are very sensitive on early detection of the changes in cochlear function and are recommended for monitor hearing in patients during chemotherapy.