The background and aim of the study is to evaluate insulin sensitivity in hyperprolactinemic subjects via euglycemic hyperinsulinemic clamp technique. Sixteen hyperprolactinemic subjects and 12 healthy subjects were included in the study. HOMA-B and HOMA-IR values of groups were calculated. Euglycemic hyperinsulinemic clamp technique was performed in both groups, and the M value of the groups was defined. Mann–Whitney U and chi-square tests were used in statistical analysis. Basal insulin level of hyperprolactinemic patients were higher than the control group (6.85 ± 4.68; 3.66 ± 0.88 μU/ml respectively; P < 0.05). Mean HOMA-IR and HOMA-B values of patients were higher than control group (1.49 ± 1.30; 0.78 ± 0.27 respectively; P = 0.02 and 136.28 ± 72.53; 64.77 ± 23.31, respectively, P < 0.001). M values of the patients were statistically lower than the control group (5.64 ± 2.36; 7.05 ± 1.62 kg/mg/min respectively; P < 0.05). (1) Hyperprolactinemic patients were more insulin resistant than control subjects. (2) Insulin resistance in hyperprolactinemic patients is not associated with obesity or anthropometric parameters such as fat content, waist circumference and BMI.