This article is focused on the effectiveness of an innovative research-based learning model that employs chemistry-based research projects in developing high school students' research competency and attitudes. The chemistry-based research projects were carried out as a part of an informal program, in real-world laboratories on 330 high school students from 2010 to 2020 integrating different branches of chemistry, including physical, organic, inorganic, electrochemistry, and biochemistry, in addition to other science and engineering areas. The chemistry subjects harmonize with many science and engineering disciplines, thus providing an immense research scope in various multidisciplinary topics. The data were collected using a mixed method by performing an indirect assessment on the program effectiveness, conducting surveys on students, research assistants, and the research faculty mentors involved in the program. The program was primarily successful in developing students' research self-efficacy and fostering their research competencies in multidisciplinary science. Further research targets to analyze the long-term effect of the multidisciplinary research experiences on their attitudes toward higher education and research-oriented careers that can contribute to a knowledge-based economy.