Few research studies have examined postintervention data from professional development interventions on science teaching and learning. Given the limited research, it is recommended that more studies examine the lasting effects of science professional development on teachers and students. The purpose of this current study was to examine the sustained changes in teachers' science teaching perceptions and process skills as a result of 2 years of an ongoing, embedded science professional development intervention. In this randomized controlled trial,experimental teachers participated in 2 types of professional development across 2 years: (a) Summer institutes (60 hr across 2 years) provided training on problem-based science curriculum units, inquiry-based instruction, classroom management, and technology use in the classroom; and (b) coaching (60 hr across 2 years) provided teachers with assistance in establishing an investigative classroom and implementing the science curriculum. Both experimental and comparison teachers followed the state science frameworks to guide their classroom instruction, but the experimental teachers implemented 1 problem-based curriculum unit in their classroom each year. Teacher data were collected 1 year after the professional development intervention was completed and compared to the data previously collected during the 2-year intervention. Results indicated that positive changes in science teaching perceptions and process skills were maintained 1 year after the professional development was withdrawn.