This chapter describes the current clinical applications of noninvasive prenatal diagnosis (NIPD) for genetic conditions and the potential use for aneuploidy screening or diagnosis. It also highlights ethical, educational and laboratory aspects that require evaluation before introduction into routine clinical practice. The main clinical indications for fetal sex determination are risk of X-linked genetic disorder and family history of congenital adrenal hyperplasia (CAH), with occasional indications including some fetal ultrasound findings and discrepancy between genetic sex and the appearances of the external genitalia on fetal ultrasound. Regardless of the approach taken, results from relatively small numbers have been reported to date and therefore considerable effort is now needed, including formal validation, standardisation, education and other work, before NIPD for aneuploidy can be considered ready for implementation in routine clinical practice. NIPD based on cell-free fetal nucleic acids circulating in the maternal plasma will gradually move into clinical practice.