Benign prostatic hyperplasia (BPH) is a common benign tumour of the prostate that becomes more common as men age. The purpose of this study is to investigate the relationships between serum zinc and testosterone in BPH patients in Iraq. This case-control study entailed gathering 90 subjects which were separated into two groups, group A consisted of 60 patients with benign prostatic hyperplasia, while group B consisted of 30 healthy males. Diagnosis revealed patient's prostate volumes (PV) were equal to or more than 25 millilitres. Both groups had their serum zinc and serum testosterone levels. The study showed that the mean prostate size was elevated significantly in the BPH group (54.0±8.4cc) as compared with the control group (19.66±2.88cc) (P:0.01). There is a significant reduction in the serum testosterone concentration of benign prostatic hyperplasia patients, (4.05±3.1 ng/ml), as compared with control subjects, (11.37±2.87; p≤0.01). There is a significant reduction in the serum zinc concentration of benign prostatic hyperplasia patients, (70.4±9.63 ng/ml), as compared with control subjects, (99.3±10.5; p≤0.01). The higher percentage of benign prostatic hyperplasia is in patients above 66 years, and the lowest is in the age group 45-55 years. Serum testosterone and zinc are significantly lower in benign prostatic hyperplasia patients than in age-matched healthy controls. All benign prostatic hyperplasia patients have larger prostates than normal healthy control participants of the same BMI. All BMI groups of benign prostatic hyperplasia patients had lower serum testosterone and zinc than normal healthy control persons of the same BMI.