Abstract: The study sought to elucidate the link between investments, oil and non-oil exports, human capital, capital goods imports and GDP on the one hand and knowledge economy in GCC countries on the other hand. The importance of the study lies in analyzing the impact of investments in the knowledge economy in the GCC during the period (2000-2015) where it has tracked the size of these investments and the extent to which GCC countries benefit from them in achieving their development. The study also contributes to the economic literature by investigating the factors affecting the four pillars of knowledge economy, using disaggregated data of the GCC economies during the 2000-2015 periods. Employing panel data analysis, we found that the expansion of capital goods imports, human capital and output reflects in strengthening the pillars of the knowledge economy in the GCC countries. Interestingly, the effects of gross fixed capital formation and oil exports were insignificant, contrary to the economic theory and the hypothesis of the study. Accordingly, it can be inferred that more investment expenditure on fixed capital formation and more efficient use of oil export earnings on knowledge-extensive activities are needed. In addition, the study uncovered the importance for the GCC countries to agree on clear and transparent objectives towards the orientation of the knowledge economy. The findings draw some main policy implications-namely, the importance of targeted education and innovation-based policy.