A sample of 162 intellectually gifted adolescents (top 1%) were administered the Strong-Campbell Interest Inventory at age 13. Fifteen years later, they were administered the Strong again. This study evaluated the intra- and interindividual temporal stability of the 6 RIASEC (Realistic, Investigative, Artistic, Social, Enterprising, Conventional) themes and the Strong's 23 Basic Interest Scales. Over the 15-year test-retest interval, RIASEC's median interindividual correlation for the 6 themes was .46; the median of all 162 intraindividual correlations was .57. Configural analyses of the most dominant theme at age 13 revealed that this theme was significantly more likely than chance to be either dominant or adjacent to the dominant theme at age 28--following RIASEC's hexagonal structure. For intellectually gifted individuals, it appears to be possible to forecast salient features of their adult RIASEC profile by assessing their vocational interests during early adolescence, but some RIASEC themes seem more stable than others.