We expect that the students of English medium schools are good and fluent in English than the students of Bengali medium schools in Bangladesh, and usually we find them as per our expectation. But in some cases we do not find it true. The students of the English medium schools of Mohammadpur area in Dhaka are fluent enough in English but the students of the English medium schools in Postogola-Sutrapur area of Old Dhaka are not. In this study, I have explored the fact that there is a big difference in the speaking proficiency in English between the students of the two areas. Not only this, the research work has found out that the socio-economic factors of the two areas are mainly responsible for this condition. We see in the study that the educational and the social-cultural and economic backgrounds of the parents and teachers of the two areas are different. We also see how these factors affect achieving the speaking proficiency in English. The study suggested the measures to improve the speaking proficiency of the students of Postogola-Sutrapur area staying in the existing socio-cultural and economical frame, as it is not possible to change the social and economic scenario of the area within a short time.