This paper presents the results of the characterization of a photonic crystal fiber stretch (PCF). The characterization is essential to know the actual parameters of the PCF for its use in subsequent projects. With the characterization results it is easier to see the differences between a standard fiber and a photonic crystal fiber. We describe the characterization process and the results obtained. The characterization included geometric parameters and spectral response, and the filtering behavior of the PCF was observed. (C) 2012 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of the Organizing Committee of the ENIINVIE-2012.