This study was aimed at investigating biochemical changes associated with benign prostatic hyperplasia in ageing men attending clinic at the university of Nigeria Teaching Hospital, Ituku-Ozalla, Enugu State, Nigeria. The assessment included 50 men with BPH attending clinic in addition to 50 healthy men (control). All samples were divided into 5 groups and with varying age ranges (Group 1 Normal control, Group 2 BPH patients ≤ 60 years, on treatment, Group 3 BPH patients ≤ 60 years, not on treatment, Group 4 BPH patients ≥ 60 years, taking treatment, Group 5 BPH patients ≥ 60 years, not on treatment).PSA levels of BPH positive subjects under treatment increased significantly (p < 0.05) compared with the control. There was a significantly (p < 0.05) high level of calcium in subjects who were ≤60 years of age that are on treatment compared with group 1 (control). Also, the level of blood urea nitrogen (BUN) recorded a high significance (p < 0.05) in comparison to the normal control. In the same study, zinc level decreased non-significantly (p > 0.05) in the groups under investigation and the level of sodium in the blood of positive treated and untreated BPH patients was non-significantly (p > 0.05) high when compared to the healthy subjects. Iron level showed a non-significant (p > 0.05) elevation in subjects ≤ 60 years of age who were on treatment and a significantly level (p < 0.05) in the other groups under investigation. Furthermore, there was a significant (p<0.05) elevation in the level of potassium ion concentration of BPH patients of group 2 and 5 as was also observed in the levels of magnesium group 2 and 4; though, the level of magnesium dropped significantly in BPH untreated group (group 3 and 5). The result of this study also showed a non-significantly (p > 0.05) higher level of selenium in BPH positive patients of all the groups under investigation compared with group 1 (normal control) while creatinine levels showed a significant (p< 0.05) elevation in all the groups being investigated when compared with group 1.