This paper aims to use data envelopment analysis in measuring and analyzing the technical efficiency of 11 agro-alimentary companies using non-parametric data envelopment analysis (DEA) models under a constant returns to scale technology. This method is often used for measurement and evaluation of decision making units. We use the term decision making unit (DMU) to refer to any entity that is to be evaluated in terms of its abilities to convert inputs into outputs. This method also shows its easiness in use and availability of softwares. We have chosen eleven companies from agro-alimentary sector in S�tif, using two inputs and one output: the two inputs are fixed assets, current and number of employees. The output is the net income. This paper shows that the major Algerian companies are inefficient and they must improve their efficiencies.