Introduction: Life Expectancy is one of the summary measures of population health, whose values and trend of changes over time show the main outcome of health system performance. Estimation of Life Expectancy is performed with direct or model-based methods. In this study direct estimation of Life Expectancy for Iran’s population in year 2003 is performed. Materials and Methods: In an ecologic study, for calculation of abridged period life table for 23 out of 28 provinces of Iran in year 2003, numbers of registered deaths for age and sex specific groups in these 23 provinces by death registration system of Ministry of Health (MOH) were used. Undernumeration of over-four year's deaths was estimated and corrected with Brass Growth-Balance method. For mortality rates of under-one and 1-4 years, similar rates from Demographic and Health Survey (DHS) 2000 with live births denominators were substituted. For total number of population of 23 provinces, information from MOH was used. Distribution of population by age and sex was taken similar to that from DHS 2003 results, and also taken as result of graduation of whole country population from 1375 census. Population of these 23 provinces was equal to 73% of total population of country in year 2003. Life Expectancy was estimated by age and sex with the obtained population and death numbers. It was assumed that distributions of population and death in 23 provinces were similar to those for the whole 28 provinces of Iran in year 2003 and hence, the estimated Life Expectancy for 23 provinces is equal to that for all 28 provinces in 2003. Sensitivity of the results to assumptions was analyzed. Confidence intervals were calculated with Monte Carlo method. Results: Life Expectancy at birth was estimated as 71.56 years for total population (95% CI: 71.52 – 71.62), 70.09 years for males (70.02 – 70.16), and 73.17 (73.10 – 73.24) for females of Iran in year 2003. Sensitivity of results to assumptions was less than 0.5%. Conclusion: Values of Life Expectancy estimates for year 2003 with direct method are higher than those based on statistical modeling approaches performed by Statistical Center of Iran and by different United Nations agencies, due to difference in estimation methods for age and sex specific mortality rates.