Résumé : This paper aims at assessing the impact of R&D activities on the number of patents applied by Belgian R&D manufacturing firms in the mid nineties. The paper extends previous work on the R&D-patent relationship by distinguishing different types as well as sources of financing of R&D activities. Another question addressed is the extent to which technological determinants differently affect the patenting of foreign R&D subsidiaries localised in Belgium as compared to domestic firms. Foreign subsidiaries appear to have a lesser propensity to patent in the host country, R&D activities exhibit slightly decreasing returns to scale with respect to patenting and important differences are observed in the estimated impacts of these activities according to their type and source of financing.