Corrosion is a ubiquitous phenomenon of metal materials in exploitation. Its mechanisms depend on the conditions in which it is located, primarily on the presence or absence of electrolytes. There are several forms of corrosion, each of which affects the destruction of metals in its own way. One of these forms is galvanic corrosion. In order to determine the incidence and impact of galvanic corrosion on metal, a gravimetric test was conducted, the results of which were analyzed from the perspective of the influence of the size of the anode, the influence of the electrolyte, and the influence of the combination of selected metals (aluminum, steel, brass) on corrosion. The conducted testing found that the corrosion rate of aluminum increases with the reduction of the aluminum surface area. The test was carried out in different electrolytes (media), namely soil, fresh water and sea water. Part of the samples was placed in the electrolyte under laboratory conditions, and part under real conditions. Test samples in laboratory conditions show a higher rate of corrosion than those in real conditions. The combination of metals also has a significant effect on the rate of corrosion. Test samples with a combination of aluminum and brass corrode significantly faster than samples with a combination of aluminum and steel, due to the greater difference in electrode potential.