This study addresses the dynamics between products and scientific and technological knowledge, identifying degree of influence on a country’s capacity to diversify their product portfolio.The transition from science to technology along with its influence on product development have been thoroughly analyzed. A better understanding of it results in a better identification of growing strategies that lead countries or regions to optimal routes of economic development. We propose to explore such transition by identifying the effect that scientific and technological endogenous capacities have on product diversification at country level. To establish the correspondence that may exist those capacities we calculated the scienceproduct and technology-product cross-proximities, indicators that allow us to measure the co-occurrence between scientific and technological categories and the product portfolio at country level, covering 120 countries between 1988-2017. Following such approach, we build the cross-space, a tripartite network, centered around a highly connected core in which the scientific, technological and product categories that are closer to each other require common capacities to rise. Additionally, by means of a three-way fixed effect econometric model, we estimated the effect of science-product and technology-product cross-densities on product diversification. Our results show that the empirical fundamentals of the principle of relatedness are valid beyond a singular field and that countries diversify to new products provided those elements are highly related to their scientific, technological and productive portfolios, confirming the relevance of scientific and technological portfolios on product diversification processes at country level.