Historically, individuals with Klinefelter Syndrome (KS), including those with non-mosaic forms, were often considered irreversibly infertile. However, current medical advancements, particularly intracytoplasmic sperm injection (ICSI), offer new reproductive opportunities even in cases of azoospermia (absence of sperm in ejaculate). Sperm can often be retrieved from testicular biopsy samples in a significant proportion of azoospermic KS patients, enabling successful pregnancies and live births. It is important to note that sperm obtained from individuals with KS may exhibit a higher incidence of sex chromosomal anomalies and autosomal aneuploidies (such as Down syndrome) compared to sperm from the general male population.