Surfaces of modern technical polymer parts are increasingly important for their functional range. In most cases the surfaces are functionalized with micro- or nano-structures to create e.g., self-cleaning properties (“Lotus effect”) or special cell growing behavior (utilized in tissue engineering or medical implants) for instance. The broad range of possible applications created multi-billion dollar industries in a mass production scale, having amazing growth rates. The structuring process using injection molding is influenced by many still unknown factors especially affecting the replication grade of micro- and nano-structures. To avoid unwanted effects (i.e. ripping off or distortion of structures during demolding), master structures are often coated with various materials. However, the influence of these coatings on the filling behavior and the replication quality of the structures are hardly investigated. In this paper, the influence of different coatings on the filling behavior and the replication quality of microstructures are investigated systematically. For that purpose several nickel masters were produced in a conventional LIGA process. They contain lines with a cross section of about 55 µm x 45 µm (height x width) which are orientated in two directions perpendicular to each other. This enables the determination of the influence of the filling direction. While one of the master structures did not receive any further treatment, the others were coated using common coating materials like Diamond-Like-Carbon (DLC), Wolfram Carbide (WC), Chrome-Nitride (CrN) and Titan-Nitride (TiN). These masters were used to carry out filling studies of micro structures on macro-scaled injection molded parts, using polypropylene (PP) and polycarbonate (PC). Additionally, the mold temperature was varied (conventional and dynamic mold temperature control). The filling behavior was evaluated using an infinite focus system followed by mathematical calculations.