Lanthanum telluride (La3-x Te-4) is a state-of-the-art n-type high temperature thermoelectric material that behaves as a weak and brittle ceramic. Vickers microindentation hardness testing was explored as a rapid analysis technique to characterize the mechanical properties of this material. An indentation size effect was observed with hardness values ranging from 439 +/- A 31 kgf/mm(2) (0.01 kgf/10 s contact time) to 335 +/- A 6 kgf/mm(2) (0.5 kgf/10 s contact time). The Vickers indentation fracture toughness, K (VIF), based on measurements of crack lengths emanating from the corners of the Vickers indents was 0.70 +/- A 0.06 MPa m(1/2).