The interprofessional education (IPE) program at Gunma University, Maebashi, Japan, implements a lecture style for the first-year students and a training style for the third-year students. Changes in the scores of modified Attitudes Toward Health Care Teams Scale (ATHCTS) and those of modified Readiness of health care students for Interprofessional Learning Scale (RIPLS) at the beginning and the end of the term were evaluated in the 2008 academic year. Two hundred and eighty-five respondents of a possible 364 completed the survey. In both the scales, the overall mean scores declined significantly after the lecture-style learning in the first-year students, while the scores improved significantly after the training-style learning in the third-year students. Exploratory factor analysis revealed that the modified ATHCTS was composed of three subscales, and the modified RIPLS two subscales. Analyses using regression factor scores revealed that the scores of "quality of care delivery" subscale in the modified ATHCTS and those of "expertise" subscale in the modified RIPLS declined significantly in the first-year students. Consequently, IPE programs may be introduced early in the undergraduate curriculum to prevent stereotyped perceptions for IPE, and comprehensive IPE curricula may result in profound changes in attitudes among participating students.