Capital structure decisions are among the most important and crucial decisions for anyrnbusiness because of their effect on the value and cost of the company. In this paper, anrnattempt has been made to examine the relevance of theoretical internal (firm level) factorsrndetermine capital structure of manufacturing share companies in Addis Ababa, Ethiopia. Tornseek answers to these questions, seven explanatory variables; tangibility, non-tax shields,rngrowth, earning volatility, profitability, age and size of the firm were regressed against therndependent variables of total debt ratio, short term ratio and long term debt ratio. Inrnconnection of this, a sample of 12 companies were take and secondary data was collectedrnfrom audited financial statements of selected companies for the period of five years (1996-rn2002EC). Stratified sampling design was employed and companies were selected based onrnsimple random to represent different industry sectors (strata) within manufacturing sharerncompanies. Data was then analyzed on quantitative basis using multivariate OLS regression.rnThe results show that tangibility, non debt tax shields, earning volatility, profitability, and sizernof the firm variables are the significant determinants of capital structure of Addis Ababarnmanufacturing share companies at least one out of the three models for capital structurernemployed in the study. While no clear and statistical proved relation are obtained for thernvariables growth of the firm and age of the firm in any of the capital structure models