Temporary Agency Work (TAW) represents a contractual arrangement based on a triangular relationship; as such it provides many benefits for the employment system. The number of TAW has been substantially increasing EU wide since 1990s. With the directive 2008/104/EC, which has been accepted in 2008, the rights of TAW employees are being equalized with other employees. TAW is not legally established in Turkey but is trying to be legalized. Academically this subject has been frequently analyzed within the fields of industrial relations, human resources management and business law. The intention of the first section is to describe the mechanism of TAW and its importance for the employment system. In the second section the progress of TAW within EU is analyzed. The last section involves a comparative study of total, female, and young unemployment rates among Germany, Italy, Spain and Turkey between the years 1998 and 2009. Also in the last section, the impact of TAW on the development of employment ratios in Germany, Spain and Italy has also been statistically analyzed with panel analysis in the last section. The TAW applications, regulations and the analysis of the impact on the unemployment status in these countries may help us to make a prediction about Turkey if TAW's are legalized.