The aim of the work is to study the relation between color Doppler flow parameters of the transmediastinal arteries, hormonal assay and testicular volume infertile and infertile men and if it could be of value in differentiating different types of defective spermatogenesis, the study included, 43 patients who were repeatedly azoospermic with clinical examination suggestive of non-obstructive azoospermia (24 male) and obstructive azoospermia (19 male). Twenty-one patient with oligozoospermia, twenty patients with asthenozoospermia, fifteen patients with oligoasthenozoospermia, and the last twenty one subjects were giving history of recent fertility within the last 2 years. Colour Doppler study of transmediastinal arteries, testicular volume and hormonal assay are useful in differentiating different types of defective spermatogenesis especially obstructive and non- obstructive azoospermia.