The strength of piezoelectric ceramics differs greatly in tension and bending tests. This effect, which is known to occur for specimens with a natural flaw population, also occurs in tests that involve Knoop-cracked specimens. In such samples, the linear-elastically computed bending strength is similar to 35% higher than the tensile strength. Computation of the actual stress distribution in the bending bars has shown that these differences are predominantly caused by the nonlinearity and nonsymmetry of the deformation behavior.