Abstract: The purpose of this research was to evaluate the morphometric effects on nandrolone used as doping in sports on humerus of rats in the pubertal term, 30 days, 60 pieces Sprague Dawley rats were used in the study. Male (n:30) and female (n:30) rats were divided into three equal groups as nandrolone, peanut oil and control groups. Nandrolone was injected 10 mg kg-1 intraperitoneally within peanut oil diluents of the commercial drug during 4 weeks as 5 days and left for 2 days of rest by the break (Nandrolone group). Peanut oil group was applied intraperitoneally like nandrolone group. The control group was no any treat. Rats were euthanatized at the end of the 4 weeks. Front extremities of the rats were dissected. Morphometric measurements were made with calipers to every one of the anatomical reference points determined of the humerus bones. Difference between humerus height averages of female peanut group, female control groups and female nandrolone group was found statistically significant (p<0.05). There was no statistically significance determined between the height of humerus of the nandrolone group (p>0.05) compared to sex difference. Cortex thickness and medullar diameter of nandrolone female humerus were statistically significant than other groups (p<0.05). As a result, it can be concluded that nandrolone used mainly athletes in the puberty period and in all athletes, stops elongation of the bones such as humerus.