This paper describes the experiences of two teachers, Ms. Santiago and Mr. Jelenik, who participated in a comprehensive National Science Foundation-supported science, technology, engineering, and mathematics (STEM) professional learning experience. This comparative case study describes how Ms. Santiago and Mr. Jelenik leveraged the justice-oriented curriculum of a STEM professional learning opportunity to transform their identities as educators while influencing their instructional practices. The professional learning experience included access to a justice-oriented curriculum introduced through monthly content-focused experiences, regular faculty learning communities, and support from an expert onsite coach. Evidence of transformed identities and instructional practices is derived from semi-structured in-depth interviews and video recordings of classroom teaching and learning. Analysis of the interview data suggests that Ms. Santiago and Mr. Jelenik found the professional learning experience transformative and that the experience served as a pedagogical identity project. Evidence from the classroom videos suggests that Ms. Santiago and Mr. Jelenik's instructional practices shifted, becoming more justice-oriented and student-centered. Moreover, Ms. Santiago's practices shifted in a manner more aligned with an engaged teaching approach. We conclude that the comprehensive STEM professional learning experience served as a pedagogical identity project while positively influencing the instructional practices of Ms. Santiago and Mr. Jelenik. Implications for preservice and in-service teacher education are discussed.