Purpose: Vietnamese children's performance on language-based processing tasks of fast-mapping (FM) word-learning and dynamic assessment (DA) word- and rule-learning tasks were investigated. Method: Twenty-one first- and second-generation Vietnamese preschool children participated in this study. All children were enrolled in 2 Head Start programs in a large city in the Midwest. All children had passed a developmental assessment and routine speech, language, and hearing screenings. All participants were taught 4 invented monosyllabic words in an FM word task, an invented monosyllabic suffix rule (-"po") meaning "a part of" in a DA rule task, and 4 invented bisyllabic words in a DA word task. Potential relationships among task performances were investigated. Receptive task performances, expressive task performances, and task totals were added to create receptive total, expressive total, and accumulated performance total (APT) scores. Relationships among receptive total, expressive total, and APT scores were also investigated. Results: Significant correlations were found between FM word, DA rule, and the receptive total. The expressive total correlated with all task total scores, APT, age, and modifiability scores. Modifiability scores correlated with the two DA tasks, expressive total, and the APT. Findings indicate that FM word and the expressive total were positively correlated with most of the other tasks, composite totals, and age. Clinical Implications: Performance on language-based processing tasks may provide valuable information for separating typically developing Vietnamese preschool children from their peers with language disorders. Practitioners should consider linguistic characteristics of target stimuli. Comparisons should include task, receptive, expressive, and APT.