Does financial market development enhance the effectiveness of R&D investment in an economy? To address this question, we apply three distinct approaches including (i) ordinary least square method, (ii) cross-country instrumental variable regression approach, and (iii) panel regression method. By using a dataset of both developed and emerging countries, we find that financial market development significantly contributes to the effectiveness of total R&D investment. This finding remains robust across different model specifications and individual estimation methods. Our finding provides an important guidance to policy makers in implementing a sound financial environment that can facilitate the total contribution of R&D investment.