Prostate cancer is one of the most common malignancies in men. Previous research has determined that androgen deprivation therapy (ADT) may be accompanied by an unfavourable metabolic profile. In this prospective study, 133 men were recruited, including 46 prostate cancer patients who had undergone bilateral orchiectomy and been on flutamide (the ADT group), 37 men with prostate cancer who had undergone radical prostatectomy (the non-ADT group) and 50 normal control subjects (the control group). All subjects were followed for at least 12 months. From baseline to 3 months, men in the ADT group had increased levels of fasting serum insulin and low-density lipoprotein compared to the other two groups (P<0.05). No obvious changes were found in the other parameters (P>0.05). After 12 months, men in the ADT group had increased levels of waist circumference, fasting serum insulin and glucose, total cholesterol, high-density lipoprotein and low-density lipoprotein compared to the other two groups (P<0.05). Additionally, the morbidity rate of metabolic syndrome in the ADT group was higher (P<0.05) compared to the other two groups. ADT through surgical castration for men with prostate cancer may be associated with unfavourable metabolic changes. The benefits of the therapy should be balanced prudently against these risks.