A common concern of economics profession was always with the determinants of economic growth. Among them, inflation was an important variable. This has significant direct and indirect effects on the economy and, upon many empirical studies, on economic growth. However, two of its most important effects, are inflation uncertainty and relative price dispersion. Hence, these three variables, together, may have a considerable impact on growth. This study is to investigate impacts of inflation, inflation uncertainty and relative price dispersion on Iran's economic growth using a VAR pattern and 1972-2007 annual data. Findings show that the rise of inflation in Iran, has been strongly accompanied by increased uncertainty within four years, and that, inflation and uncertainty has had a negative effect on real private investment growth, thereby on real GDP growth. Also, the most important effect of relative price dispersion is on the inflation in short term.