In this article, a systematic experimental study into the erosion resistance of earth plasters is presented. The erosion rate, the tile elapse till erosion failure and the amount of water leading to erosion failure are considered. Four recipes with different compositions of cohesive soil and sand combined with three different natural fibers are investigated. The natural fibers used in the tests are wheat straw, barley straw and wood shavings. Both the soil composition and the fiber content are varied in the tests. The fiber content and the fiber type are found to have remarkable effect on the erosion resistance of the plasters.