This research illustrates how a new intercultural English writing course designed for a group of Taiwanese English majors was effective in developing intercultural sensitivities. It employed a quasi-experimental methodology and used a modified Intercultural Sensitivity Scale (ISS). Results indicated that when developing Taiwanese EFL learners’ intercultural sensitivities, this new method of instruction was found to be more effective than the traditional course. It was more effective for students that began the course at a lower intermediate intercultural sensitivity level. Among the four intercultural sensitivity dimensions that were measured in a pre-test, Interaction Confidence scored the lowest while Interaction Engagement scored the highest. These findings proved that compared with the traditional skill-based English writing course, an English program which incorporated various intercultural activities could better promote intercultural learning. This then evidenced that the new course had great potential to significantly increase students’ Interaction Confidence (Experimental adjusted Mean=3.85; Control adjusted Mean=3.73), Interaction Attentiveness (Experimental adjusted Mean=3.65; Control adjusted Mean=3.43) and Interaction Respect and Enjoyment (Experimental adjusted Mean=3.83; Control adjusted Mean=3.80), which could in turn improve intercultural sensitivities on multiple levels. The research also determined the cultural learning activities that the students had preferred the most and addressed the complexity of the problems that could occur when participating in real-world experiences.