The expansion of flexible work experienced since the 1980s in developed economies is consistent with a more generic trend towards organizational flexibility, which many authors see as essential in order to compete in the dynamic global environment (Volberda, 1998). From this point of view, the changing demands of the environment have forced organizations to seek the ability to adapt rapidly and effectively as a means to be successful or even to survive. In the quest for flexibility, every area of the organization has been scrutinized in order to render it as ¿agile¿ as possible. In the human resources arena, this analysis has led to the definition of diverse ¿flexible working practices¿ (FWP) that describe a wide range of employment practices, which differ from the traditional full-time job with a fixed salary and a permanent contract. These practices have been described using other terms, such as ¿alternative¿ (Polivka, 1996; Powell & Mainiero, 1999), ¿non-standard¿ (Kalleberg, 2000), or ¿atypical¿ (De Grip, Hoevenberg, &m Willems, 1997), which coincide in denoting their divergence from the most traditional forms of employment. This article will show that quite different practices have been embraced by the common term ¿flexible working practices.¿ Subsequently, the results of empirical research regarding the implications for organizational performance of a number of flexible practices will be commented on.