Ion chromatography followed by microwave-induced acid digestion was used to evaluate the serum levels of Fe(3+), Cu(2+), Ni(2+), Zn(2+), and Mn(2+) in patients with diagnosed type 2 diabetes and in healthy controls. Recoveries ranged from 98.0% to 102% for Fe(3+), from 89.9% to 100% for Cu(2+), from 87.9% to 102% for Zn(2+), and from 89.6% to 102% for Mn(2+) were determined by examining samples spiked with various amounts of all the studied ions. The time of mineralization longer than 28 min did not affect the assay values. Precision was assessed at four unique concentrations in replicates of six, on four separate occasions. RSD was determined to be 1.16% for Fe(3+), 5.20% for Cu(2+), 2.8% for Zn(2+), and 3.75% for Mn(2+). The accuracy results (values of RSD) were as follows: 5.16% for Fe(3+), 6.35% for Cu(2+), 4.9% for Zn(2+), and 7.23% for Mn(2+). The statistical analysis confirmed that mean concentrations of Fe(3+) and Zn(2+) did not differ significantly from analogous values in the control group. Patients who additionally suffered from hypertension had higher copper concentrations compared with diabetic patients. For diabetics the presence of Mn(2+) was not stated (LOD values amounting to 0.006 microg/mL). Ni(2+) was not detectable for either the studied group or the control group (LOD=0.006 microg/mL).