This study evaluates a cross-cultural experience in science and mathematics teaching in Thailand--an internship program. In this study, qualitative data sources including semi-structured interviews, classroom observations, and pre-post questionnaire were collected from five groups of participants, which were: (a) administrators; (b) Thai cooperating teachers; (c) Thai students; (d) Thai graduate students; and (e) American graduate students. The results of data analysis from this study can be classified into six categories including: (a) role of participants; (b) value in teaching; (c) value in learning language; (d) value in learning different cultures; (e) value in professional and personal change; and (f) suggestions for the program. The research findings suggest that the future cross-cultural internship program can be developed as a school professional development program. The benefits and value that the participants have experienced are beyond the language learning.