A factor analytic study of the Test of English as a Foreign Language (TOEFL) was undertaken to determine the component abilities that underlie performance on the test for several major language groups: African, Arabic, Chinese (non-Taiwanese), Farsi, Germanic, Japanese, and Spanish. Evidence was found that three major factors underlie performance on the TOEFL and that these factors are relatively unambiguous in their interpretation. A factor underlying the listening comprehension section was noted for each language group; however, there were differences among the language groups in the interpretation of two of the factors. The African, Arabic, Chinese, and Japanese groups were generally similar on a factor underlying performance on structure, written expression, and reading comprehension items; and on another separate factor underlying vocabulary items. The Spanish and Germanic groups were also similar on each of two other factors, which correspond to the TOEFL subscores (structure/written expression, and reading comprehension/vocabulary). The vocabulary factor exhibited positive correlations with age and degree-intentions in nearly every language group, suggesting that vocabulary is the most likely of any of the abilities to develop with training or experience. Implications for the interpretation of TOEFL subscores are discussed. (SW)