Abstract BACKGROUND & AIM: Dandy-Walker malformation, a rare congenital brain malformation, is described as a triad of cystic dilatation of the fourth ventricle, complete or partial agenesis of the cerebellar vermis, and an enlarged posterior fossa with elevated tentorium. We aimed to report an association of kallmann’s syndrome and Dandy-Walker malformation.

CASE: A fifteen years old boy was referred to endocrinology department due to delayed puberty. Stages of male genital development according to Marshall and Tanner, was stage G1 and P1 respectively. in the lHRH test, peak lH level was 40th min.: 15.3 iU/ml. Peak growth hormone with insulin tolerance test was 14.5 μg/l. Olfactory test revealed light anosmia. With these findings the patient was accepted as isolated gonadotropin deficiency (kalmann’s syndrome). in computed tomography of the brain, cerebellar vermis was found to be hypoplastic and 4th ventricle was large and in posterior fossa broad hypodens area with cerebrospinal fluid density were seen (Dandy-Walker malformation). CONCLUSION: We reported an association of kallmann’s syndrome and Dandy-Walker malformation. This is second reported case probably.