Purpose – The purpose of this paper is to examine the composition of intangibles portfolio of R&D intense companies and relate it to the open innovation (OI) models they implement. It is also investigated how the internal stock of intangibles is linked to context features and performances of firms. Design/methodology/approach – The data sources the methodology relies on are audited financial statements of companies. The analysis is performed on a sample of 234 world top R&D spending firms, ranked by The EU Industrial R&D Investment Scoreboard, for the period 2010-2012, for a total of 702 consolidated annual reports examined. In order to delineate portfolio composition, we first grouped all the intangibles disclosed in annual reports in different categories and then calculated composition ratios. Furthermore, five adoption models are defined – collaboration, outsourcing, licensing, trading, and incorporation – depending on the costs, revenues, new investments and divestments in intangibles and knowledge assets related to OI. Originality/value – Our methodology points out a set of accounting indicators for both outlining companies’ portfolio composition and evaluating their OI models. With this assumption, the paper contributes to the current debate on OI by investigating both its inbound and outbound aspects after a pecuniary perspective, starting from the “acquiring” and “selling” forms of openness introduced by Dahlander and Gann (2010). Moreover, all adoption models are defined over a continuous scale, so that we do not state whether a company collaborates or not, but rather assess its degree of collaboration. Further, the work improves the understanding of the relevance of intangible assets in OI activities, estimating how the portfolio composition is linked to the implementation of OI models. Practical implications – The devised framework constitutes a useful tool for managers after both an internal and an external perspective. From an internal point of view, the tool allows to monitor the impact of the investment in intangibles on companies’ innovation processes after an open-oriented approach. As a matter of fact, it proposes a set of metrics enabling to typify companies’ internal stock of intangibles and relate its composition to the OI models adopted. From an external standpoint, given the availability and objectivity of annual report figures, the framework can be exploited as a method of comparability in order to benchmark the OI strategy of a firm, resulting from the mix of OI models, against those of its competitors.