Creosote oil is used as a wood preservative last 200 year. Especially when it’s in touch with earth where exposure to rot is high, like railroad sleepers, that in Slovenia mostly made out of beach wood. In our study, we wanted to enlighten the antifungal properties of creosote oil and the influence of anatomic features of beach wood that was impregnated with creosote oil, intended for railroad sleepers. We measured the weight of the samples of impregnated wood in absolute dray environment. With extraction after Soxhlet, we used a mixture of n-hexane and 96 % ethanol, we determined in half of the samples the creosote oil uptake, the other half we exposed to white-rot fungi (Trametes versicolor, Hypoxylon fragiforme in Pleurotus ostreatus) in line with standard SIST EN 113. Before that we artificially aged the samples by standard SIST EN 84. After 16 weeks of exposure we determined the weight loss and a link between creosote oil uptake and antifungal properties. Creosote oil uptake was not higher on the edges and lower in the middle of the railroad sleeper like we anticipated in our first hypothesis. In according with our second hypothesis the creosote oil uptake was lower in the regions were beech red heartwood was present. We confirmed our third hypothesis, that the area with less creosote oil uptake was more susceptible to rot. The findings can be used in future wood impregnation procedures.