Characteristics of each country such as culture, socio-economic and laws can shape the way that users in that country interact with products such as mobile phones. Some of these countryspecific differences may be the source of usability problems in such systems, as these systems are not usually customized based on the characteristics of the countries. The objective of this research is to explore possible ways for incorporating customization considerations in a design process aimed to solve country-specific usability problems. Based on this objective, the core research question was as follows: How can existing design methods be incorporated into a customization process for solving country-specific usability problems? To do this, it is necessary to have an understanding about the current knowledge in related fields, especially New Product Development (NPD) and Human Computer Interaction (HCI). In addition, it is essential to see if users face any country-specific usability problems when they use interactive systems. Therefore, the following sub questions were also developed: What is the state of the art in research that may provide relevant background for addressing country-specific differences and design? How do first-time users in Iran and Turkey interact with smart phones’ standard applications? The literature review phase of this study showed that in many research studies, cultural models, especially Hofstede’s model, have been used as the basis of the study. In these models, culture is usually broken down into a number of dimensions. In addition, there is a concentration on the socalled “attribute-based” approach for providing solutions for culture-oriented design or cultureoriented NPD, in which the system and the cultural specifications are broken down into a number of attributes. However, an experiment with an attribute-based method in Iran showed that users’ evaluations towards the mobile phones’ individual attributes did not reflect their final total evaluation of the devices; their total impression was different than the sum of how different individual attributes were experienced. That was why another, empirical approach was considered for the rest of the study. This approach is based on user research and observing user-system interaction in actual settings rather than modelling the users and the systems by their attributes. Using this approach, two case studies were designed and the scope of the research was limited to the smart phones. Two emerging markets of Turkey and Iran were selected for the case studies, as emerging markets similar to the ones in these countries were not studied much before. The case studies were started by interviews with local marketing teams of an Original Equipment Manufacturer (OEM). These interviews revealed the importance of innovative users in the diffusion and marketing of new products, as these users usually adapt to new technologies faster than do other members of society. The case studies in Iran and Turkey continued with focus group studies with innovative users accessed by the OEM, in order to identify areas in which country-specific usability problems may exist. Results of the focus group studies identified that Iranian users may have usability problems in using SMS and music player applications. In Turkey, the contacts and music player applications were identified as the most critical applications. In each country, two tasks were designed according to the identified areas in the focus groups for usability tests. The usability tests exhibited a number of usability problems related to these areas, along with a number of general usability problems. The cases studied were completed with requirement gathering sessions, in which innovative users generated a number of solutions for countryspecific usability problems. A content analysis showed that the participants focused on similar activities in each country. The analysis approach of this research was based on a constructive grounded theory. In this approach, the researcher is allowed to explore the influence of contextual factors on the research process and the interpretations of the researcher plays an important role in the analysis. In general, case studies demonstrated that users in both countries faced a number of countryspecific usability problems. Moreover, users who participated in requirements gathering sessions were focused on specific interaction activities in each country. The case studies also showed how local innovative users can participate in country-specific customization and how existing marketing facilities can be used for user research and country-specific customization. In addition, the case studies suggest that existing Human Centred Design methods can be adjusted for country-specific customization. As a recommendation, the results were generalized in the form of a conceptual solution for country-specific customization, and the evolutionary framework of NPD and Human Centred Design process suggested by the International Organization for Standardization was used for structuring this conceptual solution.