The present study deals with the linear elastic analysis of variable thickness rotating disks made of functionally graded materials (FGMs) by the finite element method. The disks have radially varying material properties according to an exponential law, which is achieved by the element based grading of the material properties on the meshed domain. The results are reported for three types of thickness profiles, namely, uniform, linearly varying and concave thickness, having their mass constant. The disks are subjected to the clamped boundary condition at the inner surface and the free boundary condition at the outer surface. The obtained results show that in a variable thickness rotating disk, deformation and stresses are less as compared to the uniform thickness disk.