This work has the objective of analysing the humour in the cartoons produced by the Union of Workers of the Telecommunication of Minas Gerais - Sinttel/Minas Gerais. The humour while action strategy produced fictions in the corporative speech and the Union, while was constituted by a group of organisational actors of the former Telemig/ Telemar-Minas, which possessed a worldview contrary to the one of the dominant groups - the company's high management and administration. Twenty years of periodical's cartoons - as well as the discursive strategy employed in the construction of the worldview of the union's group - have been analysed. The use of humour as a discursive strategy is very clear in the cartoons analysed, penetrating in a broad range of organisational speeches, creating modes of symbolic resistance and to inculcate Sinttel's values to the organizational participants. The analysis of the cartoons are processed under a critical approach, disclosing the ability of the Sinttel/MG to develop a discursive strategy at the organisational field.