OBJECTIVE: The objective of this retrospective study of male patients with hypogonadotrophic hypogonadism (HH) was to assess the outcome of fertility after induction of spermatogenesis by gonadotrophin injections. METHODS: During 1995-2005 17 men with HH were referred to our department for gonadotrophin treatment to stimulate spermatogenesis. RESULTS: Genetic/idiopathic hypogonadotrophic hypogonadism (IHH) was the most common cause (n = 10) followed by post-operative pituitary failure in three cases. In genetic/IHH, 5 out of 10 cases were born in the Middle East. Gonadotrophin injections induced spermatogenesis in 12 out of 13 HH men indicated by presence of ejaculated motile spermatozoa. All men with proved spermatogenesis and a paternity desire became fathers, five through assisted reproduction with intracytoplasmic sperm injection. A total of 16 children were born as a result of gonadotrophin therapy. Three spontaneously conceived singletons and two twin couples after assisted reproduction were born preterm. Two children from two separate dichorionic twin couples were diagnosed with congenital malformations. CONCLUSIONS: Gonadotrophin therapy is successful for men with HH aiming to initiate or re-establish spermatogenesis. Despite low sperm output in some of these men, the rate of pregnancies both spontaneous and after assisted reproduction, was high. More children than expected were born preterm.