BACKGROUND: Maternal parity, which is usually measured as the number of children born to a mother, has a substantial impact on the social and environmental factors around children and their development. This paper estimates the Early Childhood Development Index (ECDI) of 3- and 4-year-old children in Bangladesh and examines the relationship between maternal parity and early childhood development. METHODS: The study analysed nationally representative data from the Bangladesh Multiple Indicator Cluster Survey 2019. The dataset had 9453 children aged from 36 to 59 months. The ECDI was computed following the UNICEF's approach involving psychometric computation of four domains of development: physical, literacy-numeracy, learning and social-emotional. Since the dataset has a hierarchical structure, we used multilevel logistic regression. RESULTS: A quarter (25%) of the children were not on track in their early childhood development. Seventy-one percent were not developmentally on track in the literacy-numeracy domain, 27% were not in the social-emotional and smaller percentages were not in learning (9%) and physical (1%) domains. There was a significant negative association between maternal parity and ECDI (adjusted odds ratio [AOR] 0.95; 95% CI: 0.91-0.99). Attendance at early childhood education programmes was significantly associated with early childhood development (AOR 1.73; 95% CI: 1.47-2.03). Also, female children, those who were not stunted, located in rural areas, received parental stimulation activities, lived in relatively wealthy households or had mothers who had received secondary or further education were more likely than others to be on track of early childhood development. CONCLUSIONS: Early childhood development is negatively correlated with maternal parity. The literacy-numeracy domain constitutes the major developmental delay. Programmes for parental awareness should be widely expanded.