This study examines bilingualism’s impact on preschoolers’ psychomotor development, considering parents’ age, upbringing, and environment. A total of 183 surveys were administered to 183 children (95 boys and 87 girls), including 101 bilinguals and 82 monolingual Polish speakers. The data were analyzed via STATISTICA 10.0. The results indicate that monolinguals achieve speech milestones faster. Both groups vocalize before saying the first sentence. The time when children say their first word and sentence is significantly affected by the week of pregnancy when the baby is born. This correlation was found only in bilingual children.