Klinefelter syndrome (KS) is characterized in adults by the combination of a tall stature, small testes, gynecomastia, and azoospermia. This case is described in a North African population of the Mediterranean region of North Africa. We report the case of a male 16 years old, of Arab ethnic origin, and diagnosed with this syndrome, who had a small height in relation to a growth hormone (GH) deficiency and a history of absence seizures (generalized myoclonic epilepsy). The patient's size was <-2.8 standard deviation (SD) with weight <-3 SD. GH deficiency was isolated and confirmed by two dynamic tests (insulin - hypoglycemia tolerance test and clonidine) with normal hypothalamic magnetic resonance imaging (MRI). GH supplementation using recombinant GH was advocated, while gonadotropin treatment was deferred. Small size in children or adolescents should not eliminate the diagnosis of Klinefelter syndrome - on the contrary, the presence of any associated sign (brain maturation, delay in puberty, aggressiveness) should encourage one to request a karyotype for the diagnosis and appropriate care of any case of KS that can be associated with GH deficiency, or which is in a variant form (isochromosome Xq, 49,XXXXY).