To determine the effective volume of eugenol on day 3 in the inflamed pulp. Methods: Experimental research with a posttest-only control group design The experimental animals used were 28 male Sprague-Dawley rats. The maxillary right molar tooth was prepared with a size of 1 mm and a depth of 1 mm. Eugenol was dropped on cotton pellets according to the treatment group, namely 0.1 µL, 0.08 µL, and 0.02 µL, and aquadest as a negative control was then put into the cavity and closed with a temporary seal. Rats were decapitated after 3 days, prepared, and stained with hematoxylin and eosin. Results were read with a 100x magnification microscope at 3 fields of view and with imageJ software. Results: The average number of macrophages in the cotton pellet application group with 0.1 µL eugenol volume was 22, the 0.08 µL eugenol volume group was 6.71, the 0.02 µL eugenol volume group was 44.43, and the negative control group was 34.29. The results of the one-way ANOVA test showed a significance of 0.000 (p<0.05). Conclusion: Eugenol volumes of 0.08 µL had the lowest average number of macrophages compared to eugenol volumes of 0.01 µL and 0.02 µL, and based on the post hoc test, there was a significant difference (p<0.05).