The Internet has become in a place for the exchange and publication of data. Nowadays, Web portals serve as an important means to access information. In this context, the concepts of quality in general and of data quality in particular are highly relevant. The objective of this paper is to carry out a systematic literature review (SLR) in order to discover the state-of-the art in data quality for Web portals, and to evaluate the evolution of data quality since 2006, when another SLR was carried out, and in which a PDQM (Portal Data Quality Model) was defined. As a result, 39 attributes have been considered relevant for the assessment of data quality in Web portals.