This study explores the long-term impact of faculty-created reformed undergraduate science courses on the pedagogical content knowledge of kindergarten-6th grade inservice elementary teachers who took these reform courses during their undergraduate programs. On-site case studies were completed with 35 faculty instructors teaching entry-level undergraduate science courses at 20 higher education institutions, and 91 elementary inservice teachers. The sample was selected from a national population of diverse colleges and universities that had undergone reform in one or more of their undergraduate science courses. The data collection protocol involved classroom observations, interviews, artifact analysis, semi-structured interviews, and field notes from multiple instruments and sources. Data were collected during on-site visits from instructors and their graduated students. Quantitative and qualitative analysis identified variations in faculty instructors', as well as inservice teachers', perceptions and observations of the intended and enacted teaching goals, instruction, student difficulties, and rationale for teaching a specific science concept in observed science lessons. These perceptions and observations, identified as science pedagogical content knowledge (PCK), varied significantly among both faculty instructors and inservice elementary teachers who experienced the undergraduate reformed science courses taught by these same faculty instructors.