Designing global interfaces for users has always been a challenge. This challenge is even greater today with the current trend of globalization, which leads to highly diverse users of the same product. The global audiences for the software and information technology products belong to different countries, different religions, speak different languages, have different life styles, belong to different cultures and have different perceptions and expectations of the same product. A truly global product must inherently accommodate this diversity in order to be effective and successful. A major impediment is that there is very inadequate understanding of the role of culture in user interfaces and how they are built. This lack of understanding is further compounded by the fact that very little empirical work exists regarding the role of culture in usability testing. The objectives of this research are to study and empirically establish the effects of culture on the usability assessment technique of structured interviews. A study was conducted to determine the effects of culture on Indian participants when structured interviews are used in usability testing. The experiment consisted of usability testing of two independent groups of Indian participants by two interviewers; one belonging to the Indian culture and the other to the Anglo-American culture. The findings from the study clearly demonstrate the effects of culture on structured interviews during international user testing. Participants found more usability problems and made more suggestions to the interviewer from their own culture than to the interviewer from a foreign culture. The results of the study prove that culture affects the efficacy of structured interviews during international user testing.