By means of portals, a company can give each person the information that responds to their specific needs. Nowadays, portals tend to be constructed by means of portlets. So, if we want “good” portals, we must select the most appropriate portlets for their construction. This requires the existence of appropriate quality models to assess portlet’s diverse characteristics. Perhaps one of the most important non-functional characteristics (from the point of view of the portlet consumer) is reusability.This work aims to define a reusability model for portlets that will allow the assessment of the portlet reusability level. As an example of application, we have applied the reusability model to a concrete portlet in order to know its level of reusability.