Background In spite of usefulness of FFR in determining functional significance of a stenotic lesion, adenosine induced hyperemia still remains as a cumbersome step in FFR measurement. We sought to find a way to predict FFR value without hyperemia induction. Methods and Materials We analyzed the 644 consecutive intracoronary pressure wire study data from 411 patients performed in our hospital using a 'Radi' system from 2007 through 2011. Baseline Pd/Pa values were compared with FFR value during maximal hyperemia in order to see if there is any particular relationship. We defined FFR value as positive if FFR ��� 0.80 (FAME study criteria). Computational fluid dynamics (CFD) model with various degrees of stenosis and angulation was also applied to find the relationship between these two factors. Results A total of 644 studies, 208 (32.3%) were positive when the FAME study criteria was applied. A baseline Pd/Pa ��� 0.96 has a 97.2% of negative predictive value (NPV: 95% CI 94.2~98.9) and a 50.5% of positive predictive value (95% CI 45.5~55.5). In subgroup analysis, a baseline Pd/Pa ��� 0.96 has a 97.6% and 97.4 % of NPV in LAD and non-LAD vessel, a 99.0% and 96.3 % of NPV in proximal and mid-to distal vessel, respectively. CFD model showed an excellent linear relationship between pressure drop and coronary flow regardless degrees of stenosis and angulation, which was mainly resulted from low Reynolds number (low much less than 1000). Using this linear relationship from CFD model, FFR could not be lower than 0.80 if baseline Pd/Pa is 0.96 or greater. Conclusion We concluded that if the baseline Pd/Pa ��� 0.96, the hyperemic FFR must be larger than 0.8 on the assumption that coronary flow rate does not increases more than 5 times during hyperemia. And we found that baseline Pd/Pa ��� 0.96 has clinically very high NPV in any cases. These results would give an important massage that we do not need to induce hyperemia during intracoronary pressure wire study if baseline Pd/Pa is ��� 0.96 in most of selected cases.