Enterprise Application Integration (EAI) as a solution combines processes, standards, software and hardware for the seamless integration of different enterprise systems in order to operate and function as one. The success of EAI deployment is highly dependent on a proper selection of EAI solution patterns. ethio telecom’s enterprise systems are integrated and interoperated using EAI techniques. However, many organizations including ethio telecom, have the difficulty of selecting proper EAI solution patterns. Thus, several EAI solution pattern projects fail to deliver the service that the business is expecting. The objective of this thesis is to develop an integration pattern selection framework, which is used for the selection of an appropriate EAI solution pattern from the available real world’s design decisions. The research therefore studied the company’s end-to-end enterprise systems’ business scenario, by conducting interviews and group discussions with selected staffs, and also referred world’s scientific related works and literatures. Case study for validating the framework is also implemented. The proposed framework has the basic activities like: describing business process requirements for integration, studding the environments’ development context and integration purpose, examining the integration data and interfaces, modeling of data, mapping of those models, defining of EAI requirements specification, and finally selection of optimal EAI solution pattern, from the available EAI solutions’ patterns based on studied evaluation criteria. The framework has been evaluated using three different case studies; by taking ethio telecom’s existing integrated enterprise systems and also the forthcoming integration technology parameters. It is then reviewed and evaluated by the internal experts of the company. The main contribution of this research is: to support the company in choosing a suitable EAI solution pattern accommodating both technical and organizational measures, and to increase its’ level of success by implementing appropriate EAI solution, which avoids some drawbacks between packaged and third party systems in relation to interoperability, and flexibility issues.