The article examines the features of lexical consistency in preschool children with difficulties in speech development in the context of sensory integration. The indicators of lexical consistency in bilingual and monolingual children are compared. Lexical consistency in preschoolers refers to an organized and structured vocabulary, as well as the ability to use words in various contexts, which makes information more understandable and easier to understand. Sensory integration is understood as the process of organizing and processing sensory information from various sensory organs to adequately perceive and respond to environmental stimuli. In this study, the term "sensory integration" is considered in two senses: (1) as a natural developmental process of the sensory sphere in children, and (2) as a developmental intervention method. The study tested the hypothesis that sensory integration sessions contribute to the improvement of lexical systematization in both bilingual and monolingual children. Conducted over a two-year period (2022–2024), the study involved 117 preschool-aged children (4–7 years), including 46 bilinguals and 71 monolinguals, all diagnosed with lexical systematization difficulties. Speech development was assessed using standardized tests evaluating grammatical competence, phonetic and phonological skills, narrative abilities, and other aspects of language. Lexical systematization was evaluated using the methodology developed by O. A. Bezrukova and O. N. Kalenkova (2014), which provides comprehensive speech development metrics, including lexical structuring. Prior to participation in sensory integration sessions, all children in the experimental group demonstrated speech development significantly below age norms. This included difficulties with inflection and word formation, limited vocabulary, and impaired narrative coherence. Results from the one-sample Wilcoxon test confirmed delays in speech development across all age groups, regardless of bilingual or monolingual status. Following participation in sensory integration sessions, improvements in speech development were observed across all ages for both bilingual and monolingual children. The findings suggest that sensory integration has a positive effect on lexical systematization in children with speech difficulties, with particularly pronounced improvements observed in older bilingual children.