The positive effects of multimodal instruction have been widely assumed, but few studies have looked into the impact of multimodal tutorials within the context of an Intensive English Program (IEP). Hence, to address the research gap, the aim of this study was to investigate the impact of multimodality and tutoring assistance within an IEP on the language proficiency of EFL learners. The IEP program consisted of two phases, featuring three forms of tutoring: non-tutoring, multimodality tutoring, and multimodality mentor-tutoring. The research questions were answered using both experimental and survey methods. The quasi-experimental study was conducted (N = 467) with two fixed factors, that is, Type of Tutoring and Phase. A questionnaire was further distributed to measure students' perceptions of learning, including learning effort (LE), perception of TA scaffolding (TASCAF), and willingness to continue learning (WTL). The results of two-way ANCOVA indicated a significant effect of Type of Tutoring (p < 0.001), and interaction between Type of Tutoring and Phase (p < 0.05). Structural equation modeling testing the model fitness (i.e., LE contributes significantly both directly and indirectly through TASCAF) indicated an acceptable goodness of fit (CFI = 0.952, SRMR = 0.036, and RMSEA = 0.80), supporting the significant contribution of Type of Tutoring to students' English learning. In summary, the multimodal tutorial environment reinforced the contemporary tenet that language learning is fundamentally socially mediated. This aspect underscores the creation of a multimodal learning context with an optimal interplay among mentors, tutors, instructors, and students.