Introduction: Excessive accumulation of body fat in obesity increases morbidities such as hypertension and cardiovascular diseases. This study investigated the effect of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) supplementation on the level of high-sensitivity C-reactive protein (hs-CRP) and blood pressure in children with obesity. Methods: Fifty obese children, aged 6-10 years, were randomly assigned to the supplementation group (n=25) who received EPA and DHA supplementation or to the placebo group (n=25) for eight weeks. The trial was done in a single centre in Denpasar, Bali, Indonesia. Randomisation and allocation to the trial group were done by a computer system. The primary analysis was comparing the blood pressure and hs-CRP level between groups. Analysis of covariance (ANCOVA) and multivariate analysis of covariance (MANCOVA) tests were done to compare the differences between groups, with a p-value <0.05 considered as significant. Results: A total of 44 children completed the study, 24 (54.5%) were males and 20 (45.5%) were females. Initially, the systolic/diastolic blood pressure and hs-CRP level in the supplementation and placebo groups were 109.5/72.7 mmHg and 3.5 mg/L, 107.9/68.4 mmHg and 2.8 mg/L, respectively. At the end, they were 106.3/67.7 mmHg and 1.7 mg/L, and 108.1/71.8 mmHg and 2.8 mg/L, respectively. Systolic-, diastolic blood pressure and hs-CRP level were decreased by -2.6 mmHg (95% CI: -6.9 to 1.6; p=0.220), -7.5 mmHg (95% CI: -12.4 to -2.6; p=0.004), and -1.15 mg/L (95% CI: -2.1 to -0.2; p=0.022), respectively. Conclusion: EPA and DHA supplementation in obese children showed significant decrease in diastolic blood pressure and hs-CRP level.