The purpose of this study was to examine which of the components of executive functions (EF)--inhibition, shifting, and working memory--predict reading and mathematics achievement and if the effects of these components are the same across two cultures (Western and East Asian). One hundred twenty English-speaking Canadian (65 females, 55 males; M[subscript age] = 82.12 months) and 181 Mandarin-speaking Chinese (82 females, 99 males; M[subscript age] = 85.85 months) children were assessed on nonverbal IQ, speed of processing, rapid naming, inhibition (Color-Word Stroop), shifting (Planned Connections), working memory (Digit Span Forward and Backward), reading (word identification and reading comprehension), and mathematics (numerical operations and math reasoning). The results of structural equation modeling indicated first that among the EF components only working memory predicted reading and mathematics in the Canadian sample, while inhibition and working memory predicted reading and mathematics in the Chinese sample. The results also showed that inhibition was a stronger predictor of reading and mathematics in the Chinese sample. Taken together, these findings suggest that not all EF components are equally important for reading/mathematics and that culture may influence the relations between specific EF components and academic achievement.