monumental changes occurring on a daily basis have altered the world into a global village of expanding technology and shrinking geography in which preparing language learners for intercultural communication seems to be a sine qua non for modern language education. employing a cross-sectional design in its first phase, this study investigated the intercultural sensitivity and language proficiency of 308 iranian university seniors from seven universities. the primary purpose of this study, in this phase, was to assess the developmental level of iranian efl learners’ intercultural sensitivity, to measure its relationship with language proficiency and then to specify whether or not there were any differences in the relationship between the participants’ language proficiency and intercultural sensitivity in terms of certain ethnic and demographic background variables. chen and starostas (2000) intercultural sensitivity scale (iss) and an ethnic and demographic background information questionnaire were employed for data collection. the results of the spearman rank correlation coefficient calculation reflected a strong association between language proficiency and intercultural sensitivity and those of the chi-square test indicated that, while the relationship between intercultural sensitivity and gender, place of residence, academic major, family income, parents’ level of education and ethnic background proved to be statistically significant, such a relationship turned out to be insignificant in connection with religion and age. the impact of ethnic demographic variables on the relationship between language proficiency and intercultural sensitivity was also explored in this phase of the study. the results of the layered chi-square test and the phi coefficient showed that, although these background variables failed to influence the relationship between language proficiency and intercultural sensitivity significantly, their calculated strengths of impact, considered highly important statistically, turned out to be different. also the results of the factor analysis revealed that iranian efl learners seem to be only at the third stage of ethnocentric stages (i.e. minimization).the second phase of the study, experimental in nature, was an attempt to investigate the feasibility of enhancing their intercultural sensitivity through actual classroom training. to this end, 36 students found to be homogeneous were randomly selected as the experimental group who attended an intercultural sensitivity training course and 38 students served as the comparison group. chen and starostas intercultural sensitivity scale (iss) and an ethnic and demographic background information questionnaire were employed for data collection. the findings were gained through pretests and posttests and then subjected to such appropriate statistical procedures as the kolmogorov-smirnov technique, the wilcoxon signed-rank test, the chi-square test and the spearman correlation coefficient. the results suggested a remarkable increase in the intercultural sensitivity level of iranian efl students and their tendency to move from ethnocentric to ethnorelative stages.