Résumé : This paper compares corporate and academic patents and tests whether they have similar value and similar determinants of value. The empirical results based on an in-depth analysis of 400 biotech patents applied by Belgian universities and firms lead to the following observations : (i) the value distributions show similar levels of skewness for both academic and corporate patents; (ii) for the two sectors the identification of the institutional origin of knowledge allows for an improved understanding of what determines the value of patents; (iii) of particular importance is to separate self backward citations from non-self backward citations (to patent and non patent literature); (iv) the results clearly underline the crucial role of academic research as a source of knowledge spillovers, and the need to focus on researchers with a high scientific profile in order to crystallize their tacit knowledge into high value patents, for both the academic and corporate sectors.