Initial results have been obtained for automatic synthesis of MEMS mask-layouts using a genetic algorithm. An initial random population of geometrically valid mask-layouts (non-self intersecting 2D polygons) is produced. The fabrication of each layout is simulated using a 3-D simulation of etching. The 3-D results of the fabrication simulation are compared to a desired 3-D shape specified by users. A genetic algorithm is applied to this initial population to iteratively search for a global optimum mask-layout whose fabricated 3-D shape is sufficiently close to the desired shape. During each iteration of the genetic algorithm, the mask-layouts with fabricated 3-D shapes close to the desired shape are more likely to survive. Random shape variations with ensured geometrical validity are applied to the surviving mask-layouts to produce the mask-layouts for the next iteration. The procedure is then repeated until one or more simulated shape is sufficiently close to the desired shape to stop the iteration. Initial results demonstrate the feasibility of this approach to mask-layout synthesis.