Purpose Sentence repetition and nonword repetition assess different aspects of the linguistic system, but both have been proposed as potential tools to identify children with developmental language disorder (DLD). Cross-linguistic investigation of diagnostic tools for DLD contributes to an understanding of the core features of the disorder. This study evaluated the effectiveness of these tools for the Vietnamese language. Method A total of 104 kindergartners (aged 5;2-6;2 [years;months]) living in Vietnam participated, of which 94 were classified as typically developing and 10 with DLD. Vietnamese sentence repetition and nonword repetition tasks were administered and scored using multiple scoring systems. Sensitivity, specificity, and likelihood ratios were calculated to assess the ability of these tasks to identify DLD. Results All scoring systems on both tasks achieved adequate to excellent sensitivity or specificity, but not both. Binary scoring of sentence repetition achieved a perfect negative likelihood ratio, and binary scoring of nonword repetition approached a highly informative positive likelihood ratio. More detailed scoring systems for both tasks achieved moderately informative values for both negative and positive likelihood ratios. Conclusions Both sentence repetition and nonword repetition are valuable tools for identifying DLD in monolingual speakers of Vietnamese. Scoring systems that consider number of errors and are relatively simple (i.e., error scoring of sentence repetition and syllables scoring of nonword repetition) may be the most efficient and effective for identifying DLD. Further work to develop and refine these tasks can contribute to cross-linguistic knowledge of DLD as well as to clinical practice.