Background & Aims: Internationalization refers to the process of integrating an international and intercultural dimension into the teaching, research, and service functions of the institution. The internationalization of education emphasizes the process of including the international dimension in all aspects of education, and its main objective is to expand knowledge, abilities, attitudes, and values that are recognized at the international level. Focusing on professors as the main component of the internationalization process is vital, and their attitudes, beliefs, experiences, and levels of engagement are related to their participation in the internationalization process. One of the basic pillars of the process of internationalization of medical education is the assessment of readiness to participate in the international education market. The data obtained by this assessment is a basis for determining policies and directing academic planning. Given the growing emphasis on attracting international students and the moral responsibility of schools and departments in providing and facilitating conditions, the present study aimed to determine the preparedness of professors in educational departments of Iran University of Medical Sciences to train international students. Materials & Methods: This descriptive, cross-sectional study was performed in nine schools and 99 educational departments of Iran University of Medical Sciences in 2018-2019. The subjects were selected by the voluntary method from all professors of the university (n=900). In total, 378 professors filled the questionnaires. Data were collected through self-report, and research tools included a researcher-made questionnaire based on the professors' attitudes and abilities to train international students. The questionnaires were distributed in various groups in person. Due to the low participation of members and the problems related to access to some people, the questionnaire was subsequently emailed to the professors five times. The questionnaire contained items related to assessing the attitude of professors (14 items) and items related to assessing the ability of professors (7 items) in the form of self-report. In addition, a general question (regardless of the level of capability in the field of international student education, are you willing to cooperate in this field? Explain the causes?) was asked, and data analysis was performed in SPSS version 16 using descriptive and inferential statistics, analysis of variance, Scheffe test, independent t-test, Fisher's exact test, and Chi-square. Moreover, the open question related to the reasons for the willingness/unwillingness to cooperate in international student education was analyzed using the qualitative content analysis method. Results: In this study, the mean age of the participants was 47.08±8.04 years. In addition, the majority of the participants were female (52.1%) and had a specialized PhD or PhD (44.2%) and had the academic rank of assistant professor (54.0%). About 42.9% of the participants ...