High-strength zinc-coated bolts are used as fasteners in prestressed multi-bolted connections. This communication deals with modelling such bolts using the finite element method. The analyses were performed for a zinc-coated M12 HV10.9 bolt. Coatings with the following thicknesses were considered: 40, 60, 84 and 92 mu m. The influence of coating thickness on the selected mechanical properties of the bolt was investigated. The corresponding properties of an uncoated bolt were taken as a reference. It is shown that the use of a zinc coating with a standardised thickness is associated with a reduction in bolt stiffness of up to 11.2%.