Introduction: Misuse of anabolic androgenic steroids (AAS) has become a widespread health problem with subsequent multisystem adverse effects. However, among their adverse effects, renal toxicity remains one of the least discussed.
Aim of work: To study the histopathological effects of Nandrolone Decanoate (ND) abuse on renal cortex and examine the possible protective role of taurine.  Materials and methods: Thirty-six adult male albino rats, aging 4-6 months and weighing 200 - 250 gms, were used in this study. Animals were divided equally into three groups; Group I (control group): subdivided into Subgroup IA: negative control and Subgroup IB: rats received intramuscular 0.5ml sesame oil twice weekly for six weeks and Subgroup IC: received 100 mg/kg/day Taurine by gavage, for six weeks. Group II (ND Group): received intramuscular 5 mg/kg ND, dissolved in sesame oil, twice weekly for six weeks. Group III (Taurine and ND Group): given both Taurine and ND in the same dose and duration as subgroup IC and group II respectively. At the end of the experiment, venous blood samples were collected from the tail vein for biochemical assays. Kidneys were dissected out and processed for light and electron microscopic examination.  Results: Examination of group II revealed marked congestion, obliteration of Bowman's space and lumina of both proximal and distal tubules. Ultrastructural distortion was evident in glomerular filtration barrier and tubular lining cells. Statistically significant biochemical changes were also observed. However, group III showed almost preserved glomerular and tubular architecture with few persistent changes. Biochemical results also revealed marked improvement.  Conclusion: Marked renal cortical affection with renal functional deterioration were noted following ND. Taurine exerted marked reno-protection thus, it would be also of great help to protect AAS users against possible renal hazards in case their AAS use was inevitable.