Klinefelter syndrome (KS) is the most common chromosomal disorder associated with male hypogonadism and infertility. Parenthood can be achieved in men with KS by intracytoplasmic sperm injection (ICSI) using testicular spermatozoon. The aim of this study was to evaluate surgical sperm retrieval (SSR) rate in patients with KS and to investigate the approach associated with the highest SSR. This is a retrospective study where all medical records of patients with KS who underwent SSR for ICSI, in our centre in the past 14 years, were reviewed. Forty-three patients were included in this study. Twenty-three underwent conventional testicular sperm extraction (TESE), while 20 patients underwent microsurgical TESE (Micro-TESE). The SSR was significantly higher in the Micro-TESE group when compared with the TESE group (30% versus 0% respectively). In the Micro-TESE group, hormonal stimulation was given to 16 patients, while no treatment was given to four patients. SSR was only successful in hormonally treated patients (6/16). When the type of hormone stimulation was evaluated, SSR was higher in patients receiving aromatase inhibitors (27.8%). SSR in patients with KS is significantly higher when using hormonal stimulation by aromatase inhibitors followed by microsurgical testicular sperm extraction.