Constructivist-based pedagogy is particularly applicable to gifted secondary students in the sciences due to the increased background knowledge of the population and the nature of the study of science. This research was an investigation of the effectiveness of a residential constructivist-based summer learning experience in aquatic biology and biomedicine for gifted secondary students. Both quantitative and qualitative approaches were used to analyze the data. Quantitative analyses showed that the program significantly increased both scientific knowledge and conceptual understanding of science among participants. There was no change in academic self-concept of the participants. Qualitative results supported these findings and demonstrated the importance of social relationships for program effectiveness. These results have implications for researchers in constructivist theory, science, and gifted education.