The study focuses on the connection between the birth-order in a sibling constellation and the creativity and personality traits of adolescents. The study searches for the answer to questions of whether creativity is connected with the birth-order in the sibling constellation (in the sense of the position among siblings and gender) and what personality traits it is connected to. The personality traits of the individual positions in the birth-order (first-born, second-born, the middle, the youngest and the only child) are compared. The Torrance Test of Creative Thinking (TTCT) and the Urban Creative Thinking Test (TSD-Z) were applied for creativity identification. To measure personality dimensions, the NEO Five-Factor Inventory was applied to a sample of 158 adolescents - University students of humanities and artistic-technical departments (mean age 19.91 years). The data on family constellation (birth-order, size of family, family and sibling constellation, age differences, etc.) were gathered, based on our own Questionnaire of Family Constellation. Our results confirmed the higher performance of the second-born adolescents in the Torrance Creative Thinking Test. The adolescents that grew up with a sibling of the same gender were more conscientious and more extravert. The creativity performance of a woman was higher if she grew up with a brother and a sister. The men growing up with a brother and a sister were more agreeable than the women in the same sibling constellation.