Abstract Potentially malignant disorders (PMDs) of oral cavity and oral cancer remain a cause of serious concern despite intensive research and development. Diet and immunity have been identified to play a crucial role as modifying factors in these diseases. Our study intended to explore this relationship by estimating and comparing the serum levels of copper, iron and circulating immune complexes (CICs) in patients diagnosed with PMDs and oral cancer and normal healthy individuals. In this study, 40 histopathologically diagnosed cases of PMDs and oral cancer were included along with 30 healthy controls and 5 ml of venous blood was drawn using venipuncture. Serum estimation of copper, iron and CIC then followed using the colorimetric and spectrophotometric methods. The data obtained was subjected to statistical analysis using one way ANOVA and Pearson's Product-Moment Correlation Test. The mean serum copper level was measured as 138.98 ± 10.13µg/100ml in the PMD group and 141.99 ± 21.44 µg/100ml in the oral cancer as compared to 105.5 + 18.81µ/100ml in the controls. The mean serum CIC levels was highest in the oral cancer (9.65 ± 0.16OD470) followed by the PMD group (0.18 + 0.21 OD470) and least in the control group (0.048 ± 0.02OD470). Whereas, the serum levels of iron showed a significant decrease in the PMD group (110.9 ± 10.54 µg/100ml) and the oral cancer group (114.29 ± 25.83 µg/100ml) as compared with the control group (136.85 ± 14.48 µg/100ml). There was no positive correlation obtained between the three groups with respect to the chosen parameters indicating that the variables were independent of each other. It can be thus be ascertained that trace elements like copper and iron as well as humoral responses (CICs) have a close relationship with PMDs and oral cancers.