This paper represents a testing method to directly measure the suction-controlled tensile strength of compacted clays under a constant, initial soil structure. Test results of a medium plasticity clay are shown as an example. The induced suction is 0 to about 140,000 kN/m². The tensile strength of the compacted clay reaches about 450 kN/m² as a maximum. In addition, analytic calculations based on the capillary theory show values in the same magnitude but underestimate the test results.