Monosodium glutamate (MSG) is widely used in food preparation industry and has been consumed regularly. Previous studies had reported on effects of MSG when given at extremely high dosages, the results are not applicable to human equivalent intake. Therefore, the present study aimed to evaluate the effect of MSG on sperm quality and changes in reproductive organs of adult male rats when taken at average human daily intake (ADI). Twenty-four adult male rats were randomly assigned into three groups; NC (Normal control), MSG60 and MSG120 where MSG was given orally at 60 mg/kg and 120 mg/kg to each respective group. All treatments were conducted for 28 consecutive days. MSG at estimated ADI of 120 mg/kg body weight resulted in a significant drop in sperm quality (p