The purpose of this study was to investigate the effects of mentorship on students gifted in mathematics and science. The study aimed to address an experimental study of mentorship on 42 gifted junior-high students. Instruments consisted of the ”Inventory of Learning Behavior” and a self-designed ”Survey of Effects of Mentorship”. Obtained quantitative data were analyzed by t-test, Chi-square test, and percentage, while the qualitative, interview data were content analyzed. Main research findings were as follows: (1) In terms of the value of the project, 86.8% students showed positive attitudes. Also, most of them reported that they were willing to attend similar programs if provided again. (2) With regard to the outcome, most teachers, students, and their parents believed that a project like this was beneficial. (3) In the follow-up survey after six months, students reported that this project was benefited to their senior high school adjustment in academic, living, psychological, and interpersonal areas. Based on the above results, recommendations were made to teachers of the gifted, gifted students, their parents, and schools for future implementation and suggestions for future studies were also discussed.