This work aims to analyze the effects of the Laser Surface Remelt Treatment (LSR) on Al-11%Si-5%Ni alloy's microhardness and microstructure. The operational parameters of the laser involved in the treatment were scanning speed (V) and power (P). Fourteen tracks resulting from the combination of these parameters were analyzed by optical and scanning electronic microscopes (OM and SEM, respectively), observing the dimensions of the remelted pool and the change in the microstructure. Vickers microhardness tests were conducted to examine the effects of LSR on the surface and X-ray diffraction (XRD) was performed on treated and non-treated alloy samples to examine the present phases. The increase in P resulted in the increase in the pool dimensions, while the increase in V presented the opposite effect. The LSR was very effective in the refinement of α-Al dendrites and interdendritic eutectic region, with a minimum primary dendritic spacing of 0,86 µm. The Vickers microhardness increased up to 105% for sigle tracks and 76% for overlapped tracks, comparing to conventional casting.