Using "Education Watch" database of 2008, this article explores the factors associated with learning achievement of primary school students in Bangladesh. The sample consists of 7,093 fifth graders (final year of compulsory primary education) from 440 primary schools. Based on nationally adopted competencies for primary education, a group of experts collectively developed and validated the test instrument used for assessing students' learning achievement. The other data were collected through interviewing the parents of the students and the school heads. Students' socio-economic background, school-related factors and additional educational inputs were found associated with their learning achievement. The order of the set of factors in terms of affecting learning achievement was socio-economic background, additional educational inputs and school-related factors respectively. Fathers' education and receipt of supplementary private tuition were found to be the two most important factors associated with learning achievement; however, guardians' attendance in school meetings, religion and area of residence had the least influence. (Contains 5 tables.)