The objective of this study is to evaluate objective changes in water content, sebum content, transepidermal water loss (TEWL), and melanin due to breast cancer chemotherapy, and their association with subjective symptoms. Prospective cohort study of 61 patients 18 years of age or older with a postoperative diagnosis of stage I-III breast cancer, who received adjuvant chemotherapy between February and September 2012 at an outpatient breast cancer clinic in Korea. Objective skin parameters, measured using a noninvasive bioengineering device, and patient-reported dryness and dullness were assessed before chemotherapy, after two cycles of chemotherapy, and 1, 3, and 6 months after completion of chemotherapy. Water content (-6.5 %), sebum (-75.5 %), and TEWL (-22.4 %) significantly decreased during chemotherapy compared to pre-chemotherapy levels (all p values <0.001). These parameters were lowest at 1 month after completion of chemotherapy and recovered thereafter but did not return to baseline levels after 6 months of follow-up. Melanin increased during chemotherapy with respect to pre-chemotherapy levels (8.4 %; p < 0.001) but decreased from the first month after completion of chemotherapy through the end of follow-up (-17.1 %; p < 0.001). The patterns of skin changes were similar in patients with or without hormone therapy. Most of patients reported dryness (57.9 %) and dullness (49.1 %) after chemotherapy, and patient-reported dryness was significantly associated with decreased sebum content. Chemotherapy-induced substantial changes in objective skin composition parameters. These changes persisted after 6 months from completion of chemotherapy and were associated with patient-reported symptoms. Additional research is needed to translate these findings into interventions for improving the dermatologic quality of life of breast cancer patients undergoing chemotherapy.