Objective To establish and assess a rat model of benign prostatic hyperplasia (BPH) complicated with late-onset hypogonadism (LOH). Methods A total of 80 SD rats were randomly divided into 4 groups:control group, BPH complicated with LOH (model) group, BPH group and LOH group, with 20 rats in each group. In the model group, intraperitoneal injection of cyclophosphamide (20 mg/[kg·d]) was continuously administered for 5 days, followed by continuous intraperitoneal injection of testosterone propionate (50 mg/[kg·d]) for 28 days; the rats in the BPH group were treated the same as that in the model group, except with the same volume normal saline instead of cyclophosphamide; in the LOH group with same volume lucca oil instead of testosterone propionate; and in the control group, the rats were treated with same volume normal saline instead of cyclophosphamide and lucca oil instead of testosterone propionate. Two days after drug withdraw, serum testosterone was detected and weight loading swimming test, tail suspension test and sexual behavior test were performed. Then prostate weight and pathology were determined after the rats were sacrificed by cervical dislocation. Results The mean prostate indexes of rats in the LOH, model, control and BPH groups were 1.58±0.13, 2.93±0.19, 2.33±0.13 and 3.23±0.11, respectively; serum testosterone levels were (4.91±1.06), (9.52±1.02), (12.59±0.70) and (19.69±0.56) ng/mL, respectively; the tail suspension struggling times were 97.40±15.86, 120.40±14.06, 223.83±16.51, and 235.29±18.77, respectively; the weight loading swimming times were (74.27±9.29), (167.47±23.35), (302.33±30.10) and (261.59±35.13) s, respectively; the times of olfactory sensation were 1.53±0.52, 3.07±0.88, 9.17±1.30 and 9.59±1.12, respectively; the mean ride across times were 0.33±0.49, 0.47±0.52, 2.11±0.47 and 2.29±0.47, respectively. Statistical analyses showed that there were significant differences among the four groups in mean prostate index, serum testosterone level and tail suspension struggling time (P<0.05, P<0.01), in weight loading swimming time and time of olfactory sensation (P<0.01) except between control group and BPH group, and in mean ride across time (P<0.01) except between control group and BPH group, and model group and LOH group. Conclusion A BPH complicated with LOH rat model was successfully established with intraperitoneal injection of cyclophosphamide and testosterone propionate.