The purposes of this study were to (a) examine the presence and prevalence of the big-fish-little-pond effect (BFLPE) in summer programs for the gifted, (b) identify group and individual difference variables that help predict those who are more susceptible to the BFLPE, and (c) put the possible BFLPE on academic self-concept in a larger context of self-concept stability and change during adolescence. Longitudinal data were gathered from adolescents participating in a summer program for the gifted over a 3-year period. The results indicate no prevalent patterns of declines in academic self-concepts after participating in summer programs, though suspected cases of BFLPE can be identified, and there was evidence pointing to the moderation of the BFLPE by gender and self-esteem. Longitudinal patterns of self-concept stability and change also show no consistent pattern of long-term effects on self-concept. Implications of these findings are discussed that highlight developmental, social, and individual conditions under which the BFLPE may exert itself and conditions under which it may be mitigated. (Contains 6 tables, 5 figures, and 1 note.)