Prior research has displayed effects of bilingualism on inhibitory control in preschool children. However, these effects only held for ‘conflict tasks’, and not delay of gratification tasks, and other domains of executive functioning were not explored. For older children, prior research has found relationships between bilinguals’ advantages and home language environment. This inquiry explores effects of bilingualism and bilingual home language environment on executive functioning in three-year-old children. 200 bilingual and 829 monolingual three-year-olds performed tasks of inhibitory control, working memory, and selective attention. Home language environment features were evaluated via a parental questionnaire. The bilinguals surpassed the monolinguals on a conflict task only, and this effect was very small. Further assays displayd wider effects on inhibitory control that were linked to home language environment: Bilinguals whose parents spoke different languages surpassed bilinguals whose parents spoke the same language on both the conflict task and a delay of gratification task.