Cellulose extracted from waste newspaper was methylated using dimethylsulfate to produce methylcellulose with degree of substitution of 1.46 +/- 0.06. This material was characterized by FTIR and DSC. An aqueous dispersion of methylcellulose was used to produce mortars of Portland cement (CPV-ARI). The results showed an increase on the consistency index with the production of a system that presented good workability, homogeneity, and high viscosity, which was corroborated by the tacky aspect of the produced mixture. Hardened mortar presented an increase in the potential resistance to traction adherence when compared to the reference mortar. Those characteristics indicate that this material could be used in situations that need good workability, increasing on viscosity and adhesive properties, such as in tile installation, covering, and finishing. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 118: 1380-1385, 2010