The purpose of this study was to determine the effect of iron powder as filler material on the characteristics of asphalt. The research was begun by testing the physical properties of pure asphalt. These tests provided the necessary information needed in order to establish a baseline for further research, as well as to produce materials for testing. The next step was making a specimen of pure asphalt by mixing the bitumen, soft aggregate and coarse aggregate to an optimal asphalt content of 6%. From the specimen, six samples of asphalt were prepared. No modifications were made to the first sample. The remaining samples of asphalt were modified by adding iron powder as a filler in increasing percentages, as follows: 0,5%, 1%, 1,5%, 2%, and 2,5%. A Marshall Test was conducted on each sample to determine the characteristics of the asphalt samples, including stability, density, flow, VIM, VMA, and VFA. Based on the test results, it can be concluded that the addition of iron powder affected the physical properties of asphal