The objective of the study was to evaluate arterial morphologic changes of early atherosclerosis and changes in procalcitonin (PCT) levels in patients with acromegaly according to disease activity. Thirty-three active and 20 inactive acromegaly patients followed at Endocrinology-Metabolism out-patient clinic of Cerrahpasa Medical Faculty between 2004 and 2008 were included in the study. Twenty gender and age matched healthy subjects were included as the control group. Intima-media thickness (IMT) of the carotid arteries was measured by ultrasonography. Blood was drawn for biochemical tests and the serum concentrations of C-reactive protein (CRP) and PCT. Intergroup analysis revealed no significant differences between Growth hormone (GH), insulin like growth factor-1 (IGF-1), and IMT (P = 0.42, P = 0.47 respectively). No significant differences were found in the fibrinogen, CRP and PCT levels of the acromegaly patients and the subjects in the control group (P = 0.57, P = 0.84, P = 0.68 respectively). In the patients with IMT ≥ 1 mm, PCT (0.4 [IQR: 0.4-0.55]) levels were significantly different from the patients without atherosclerosis (0.06 [IQR: 0.05-0.12], P < 0.001). The correlation between IMT and PCT (P = 0.001, r = 0.47) was more significant than the correlation between IMT and CRP (P = 0.01, r = 0.28). There was a positive correlation between IMT and atherosclerotic risk factors such as age (P = 0.01, r = 0.27) and body mass index (BMI; P = 0.005, r = 0.32). Our results showed that PCT increases before CRP and it can be useful for the assessment of premature atherosclerosis in acromegaly as well.