Introduction: Children living in orphanages tend to be neglected and may be malnourished. This study assessed the socio-economic background and nutritional status of children living in an orphanage in Dhaka city, Bangladesh. Methods: A cross-sectional study was conducted among the children in Sir Salimullah Muslim Orphanage, Dhaka from January to November 2014. Systematic sampling was adopted to collect data from 232 children using a semi-structured questionnaire. Anthropometric measurements of the children were taken and the WHO reference growth chart was used to determine the children’s nutritional status. Weight-for-age was categorised by mild, moderate and severe malnutrition. The Pearson Chi-square test was performed to determine the association between the extent of malnutrition and socio-demographic characteristics of the children. Results: The majority of the children (60.3%) in the orphanage were malnourished, with mild, moderate and severe malnourished being 43.1%, 16.8% and 0.4%, respectively. Malnutrition was higher among the boys than girls in the age group of 15-18 years. The orphans suffered significantly (P<0.05) from malnutrition compared to those, who had at least one parent alive. Conclusion: Malnutrition is highly prevalent among children and adolescents under residential care and needs to be addressed. In particular, early identification and intervention can improve the quality of nutritional status of the urban orphanage population. An investigation with a large sample is highly desirable to explore the severity of the problem in the national context.