This study investigated the Mean Length of Utterance in words (MLUw), Mean Length of Utterance in morphemes (MLUm), and the use of Lexical Morphemes (LM) and Grammatical Morphemes (GM) in Bangla-speaking children with Down Syndrome (DS) in comparison with Typically Developing (TD) children. A total of forty Banglaspeaking children participated in this study. Twenty were TD children of age 4 to 6 years, twenty were children with DS aged 7 to 11 years. Each was divided into two age groups. The study adopted a quantitative approach and narrative data was collected using the Picture-Narrative Task and the utterances were audio recorded. The first 50 intelligible utterances from each child were transcribed and analyzed considering: MLUw, MLUm, Lexical Morphemes (nouns, verbs, and adjectives), and Grammatical Morphemes (pronouns, prepositions, and conjunctions). The results suggested that there was a significant difference between TD and DS. The TD participants had a higher mean score than DS in each group. The between-group comparisons suggested that the higher the age the higher the MLU and the MLUw and MLUm had a positive correlation for TD and DS. Overall, children with DS have significantly lower MLUw and MLUm in comparison with TD children which indicates language deficits in children with DS. This study may provide guidelines to assist Speech and Language Pathologists (SLPs) in formulating assessment and intervention strategies for Bangla-Speaking children with DS and children who are at risk of language impairments. Furthermore, this study may also assist clinicians working with Bangla-speaking bilingual children.