Objective To retrospectively analyze the relationship between benign prostatic hyperplasia (BPH) and metabolic syndrome (MS) in senior patients. Methods The 859 male senior patients including 619 cases with BPH and 8 cases with MS were enrolled in this study, and there were 192 cases with both diseases and 40 controls. The levels of fasting blood glucose (FBG), total cholesterol (TC), triacylglycerol (TG), low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C) were measured. The body mass index (BMI), prostate volume and annual prostate growth rate were determined or calculated. The correlations of BPH with other metabolic risk factors were analyzed. Results The levels of systolic blood pressure (SBP), diastolic blood pressure (DBP), body weight, BMI, TG and FPG were higher (t=6.15, 5.99, 13.12, 15.56, 10.63 and 9.94, all P＜0.01), while serum HDL-C level was lower (t=-7.57,P＜0.01) in BPH patients with MS than without MS. As the number of components of MS was increased, the prostate volume was increased (F=2.98, P=0.031). As the age, body weight, BMI, SBP and PG were increased, the prostate volume was increased (t=-6.39,-2.39,-2.36,-2.13,-25.85,all P＜0.05). Spearman analysis showed that prostate volume was positively correlated with age, SBP, body weight, BMI and hypertension (r=0.229, 0.079, 0.090, 0.089 and 0.088, all P＜0.05). And age, body weight and SBP were the independent risk factors for BPH (OR=1.07, 1.03 and 1.34, all P＜0.05). Conclusions The present study demonstrates a relationship between BPH and MS in senior patients. Future studies are needed to confirm our results and to explain underlying mechanisms.