Abstract: The usage of use case models has been progressively used to capture and depict the functional requisites of a software system. There are different approaches and methods to successfully count on effort using use cases. A few researchers tested use case points methods and revealed that it has the potential to be a reliable source of estimation alike the function point method. Estimation of size of software development projects has a strong effect. Use case modeling is increasingly being utilized not only to describe the software and system requirements and a basis of design, development, testing, deployment, configuration management and maintenance but also to have an estimation method that makes the use of them. Perhaps this study aims at the potentiality of use case point`s method for estimating the size and effort of software development projects, including the major limitations and offers some possible rectification.