<p>Glass flakes are frequently claimed to improve the resistance of organic coatings to mechanical loads. This contribution is concerned with effects of glass flake addition to multilayer organic coating systems with epoxy interlayers on their resistance against abrasive wear, compression loads and impact loads. Four pairings with two layers of epoxy and one polyurethane/polysiloxane topcoat each are manufactured and tested. Each pairing features a system with epoxy layers without glass flakes and a system with epoxy layers with glass flakes. Relevant resistance parameters for the three loading cases are introduced, namely abrasion resistance (wear), contact stiffness, damage area and first maximum force (compression), and first maximum force and deflection at maximum force (impact). The effects of glass flakes on these parameters are investigated via scanning electron microscopy (SEM) inspections and are evaluated with statistical methods. The results reveal that, statistically, glass flakes do neither significantly improve nor significantly deteriorate the resistance of the investigated coating systems against these types of loading. The effects depend on the load intensities. Three working hypotheses have been formulated to explain a possible worse performance of glass flake-reinforced epoxies under mechanical loads: 1. glass flakes introduce a weak interface (flaw) between the flake and the polymer matrix; 2. the glass flakes added to a polymer matrix act as a stiff inclusion in a soft matrix, generating stress concentrations; and 3. glass flakes reduce the capability of the composite material to plastically deform and shift the material response to a linear elastic (brittle) mode. </p>