Salt sensitivity exhibits sexual dimorphism which is higher in males when compared with females (1). This has been attributed to the effect of androgens on blood vessels in males (2). Sodium overload, which is present in high salt diet (HSD) has been reported to change the shear stress and geometric modifications of the blood vessels (3) and haemodynamic factors are very important in the regulation of the structure of the artery (4). Therefore, experiments were designed to study the vascular smooth muscle histomorphometry in orchidectomy-induced (under ketamine and xylazine: 90mg and 10mg/Kg/body weight i.m respectively (5) androgen deficient rats placed on a normal (0.3%) or high (8%) NaCl diet for 6 weeks, with or without testosterone replacement (10mg/kg bodyweight sustanon 250® i.m once in 3 weeks). Histological examination of thoracic aorta and mesenteric artery were carried out with specific dyes; haematoxylin and eosin stain for the cytoplasm and nucleus and Verhoeff – Van Geison and Picro-sirius red stains for elastin and collagen content estimation respectively. Histomorphometric analysis was done using a programmed software IMAGE-PRO 3DS 6.1. Tunica media thickness and cross sectional area, elastin and collagen contents were all significantly elevated (P < 0.05) in the rats placed on HSD while orchidectomy significantly reduced the values of the parameters in HSD group but concomitant administration of testosterone restored them to the levels observed in intact rats. Orchidectomy ameliorated vascular hypertrophic effect of a HSD by reducing vascular smooth muscle proliferation and decreasing extracellular matrix protein deposition induced by HSD. Testosterone replacement following orchidectomy accentuated vascular hypertrophic effect of a HSD.