Prenatal treatment of congenital adrenal hyperplasia with dexamethasone (DEX) has been in use since the mid-1980s and has proven effective at reducing virilization of external genitalia in affected girls. However, multiple experimental studies on animals and clinical studies on humans show that prenatal administration of glucocorticoids may cause unwanted adverse effects which have raised concerns about the long-term safety of the treatment. The long-term outcome of prenatal DEX treatment on cognition has been investigated, but the results are still conflicting. Overall, most of the evidence points towards a negative effect on executive functions where girls seem to be more susceptible than boys. Some effects on social behavior have been observed, but results are still contradictory and treated children are mostly well adapted. Cardiovascular, renal, and metabolic function are still areas to be investigated. Larger studies are warranted to investigate areas other than cognition and behavior and to be able to draw more definitive conclusions about prenatal DEX treatment.