Aim: To investigate the relationship of serum lipoprotein(a) [Lp(a)] and other serum lipids with presence of Graves' ophthalmopathy (GO). Methods: A total of 99 consecutive patients diagnosed with Graves' disease (GD), aged 18-65 years, who had not received prior treatment for GO, thyroid surgery, or radioactive iodine therapy, were recruited between June 2020 and July 2022. In addition, 56 healthy controls (HCs) were included as the control group. All patients underwent an ophthalmological examination, and were classified based on the presence of GO into the GO group (n = 45) and no GO group (n = 54). Fasting blood samples were collected from all participants to analyze serum lipid parameters, including Lp(a), total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, and triglycerides. Results: The median serum levels of Lp(a) were 5.7 [4.3-9.2] in the GO group, 6.7 [3.7-9.9] in the no GO group, and 4.7 [3-7.6] in the HC group. The intergroup comparisons of serum Lp(a) levels showed no significant result. The serum levels of total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides were also similar between the groups (P > 0.05 for all). However, when analyzing only euthyroid GD patients and the control group, the serum LDL cholesterol levels were found to be significantly higher in the euthyroid GO group [median: 132 interquartile range (IQR) (110-148) mg/dL] than in the HCs [median: 96 IQR (94-118) mg/dL] (P = 0.002). Conclusion: The findings of our study did not support the association between serum Lp(a) levels and GO.