Cavitation erosion causes serious problems for hydraulic machinery. Selective laser melting (SLM), is a type of additive manufacturing that can produce metal parts directly and it has begun to be used in various industrial settings. However, the erosion properties of the SLM processed parts have only rarely been reported. The paper addresses the cavitation erosion behavior of AlSi10Mg samples fabricated by SLM at different laser scanning speeds. A wrought sample was also tested to provide a basis for comparison. Sample hardness and microstructure were investigated. Results showed the cavitation erosion behaviors of SLM samples to differ greatly from that of the wrought sample. The erosion rate of SLM samples was found to peak in the first 30 s. This was accompanied by the removal of particles inside pores. After peaking, the erosion rate of the SLM samples decreased significantly. SLM samples showed an extremely low erosion rate entering the steady-state period. Large, deep craters which were common wear marks on the wrought sample, were not present on the SLM samples. Different scanning speeds resulted in different max erosion rates.