Introduction:It is not yet known how Caesalpinia sappan L. extract (CSE) affects the activity of SOD and MDA levels in rats exposed to inhaled formaldehyde. Method: This true experimental study in vivo uses a randomized post-test-only control group design. The subjects were male Sprague Dawley, 2-4 months old, weight 200-300 grams, a total of 30 heads divided into 6 experimental groups. The treatment group was given CSE at doses of 0, 100, 400, and 1000 g/kg BW for 28 days, and exposed to inhaled formaldehyde for 2 weeks, and 8 hours/day. SOD and MDA were measured using the ELISA kit. Statistical analysis used Kruskall Wallis, Mann Whitney, and rank spearman tests with α= 5%. Results: The highest average SOD was in the CSE 1000 group and the lowest was in the negative control group. The highest average MDA levels were in the negative control group and the lowest was in the positive control group. The difference in SOD levels between groups with a p-value = 0.016, while the difference in MDA between groups has a p-value of 0.915. the p-value of the relationship between SOD levels and MDA levels is 0.02 (correlation coefficient = -0.422). Conclusion: Caesalpinia sappan L. extract can increase the activity of superoxide dismutase enzymes but has not been able to suppress malondialdehyde levels. There was an association of increased superoxide dismutase enzyme activity with decreased malondialdehyde levels in Sprague Dawley exposed to inhaled formaldehyde