Previous studies have shown 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 investigated. For older children, previous studies have found relationships between bilinguals’ advantages and home language environment. This study investigates 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 characteristics were assessed through a parental questionnaire. The bilinguals outperformed the monolinguals on a conflict task only, and this effect was very small. Further analyses showed broader effects on inhibitory control that were related to home language environment: Bilinguals whose parents spoke different languages outperformed bilinguals whose parents spoke the same language on both the conflict task and a delay of gratification task.