Fatigue, rated by adolescents as the most distressing symptom experienced during cancer treatment, is essential to the successful clinical care of patients of every culture and nationality. Efforts to provide relief from such symptom, in any area of the world, have been hampered by the lack of reliable and valid instruments used to measure fatigue. Our aims were to examine the semantic, conceptual, and normative equivalence of the Chinese version of the Fatigue Scale-Adolescent (FS-A-C) to the original Fatigue Scale-Adolescent (FS-A) and to estimate the reliability and validity of the FS-A-C. We recruited 51 Taiwanese adolescents in various stages of different types of cancer in this cross-sectional study. Results indicated that the initial panel estimates of semantic, conceptual, and normative equivalence of the FS-A-C with the original instrument (FS-A) were positive. The FS-A-C had acceptable internal consistency (Cronbach α = .89) and moderate-to-high content validity (content validity index ranges from 87% to 100%). In addition, the FS-A-C achieved known-groups validity (anemic adolescents reporting higher fatigue than nonanemic adolescents do) and initial construct validity (a significant association between the FS-A-C and the Anxious/Depressed subscale). Its use in measuring the intensity of fatigue in adolescents is likely to yield accurate assessments of their fatigue that could prompt clinical efforts to relieve their fatigue-related distress.