The purpose of this mixed methods study was to examine the influence of participating in a STEM Academy (STEMA) on girls' mathematics, science, engineering, and technology self-efficacy and STEM attitudes. Twenty-eight sixth grade girls participating in a STEMA were individually matched with sixth grade girls not participating in a STEMA. Both participant groups were administered the "Student Attitudes toward STEM" (S-STEM) -- "Middle and High School Survey" and the STEMA group also participated in a focus group. The results indicated that the STEMA program did positively influence girls' mathematics and science self-efficacy but not their engineering, technology, or STEM self-efficacy. Self-efficacy perceptions were positively influenced by their participation and the teachers in the STEMA program.