Abstract: An 8-node solid assumed stress finite element with a traction-free cylindrical surface is developed based on the Hellinger-Reissner principle. The assumed stress field satisfies the equilibrium equations in the element as well as the traction-free conditions over the cylindrical boundary. In the limit plane problem case, the assumed stress field also satisfies compatibility conditions. The stress concentration problems of a thick or thin plate with semicircular notches under uniform tension and in-plane bending are analyzed using the hybrid stress element. Numerical results show that good accuracy is achieved for the distributions of the circumferential stresses and the stress concentration factors.