An expanded matrix was obtained from the simple screw extrusion process using a mixture of starch and cassava flour. Two experimental designs were made: the first design included two factors, cassava flour content and moisture percentage and the second design used two factors, temperature profile and screw speed. The respective combinations of the experimental designs that presented outstanding mechanical properties were the mixture with 15 % flour and 22 % humidity, at process conditions of 100 rpm and 125 °C. Under these conditions, an expanded material was obtained, which, presented a high density, low expansion index and high resistance to compression.