This article presents the main characteristics of the Continuous Sample of Working Histories (MCVL), a dataset with administrative information about more than one million workers and pensioners in Spain. We study the pros and cons of this dataset particularly emphasizing its comparative advantages for analyzing job mobility. Moreover, we explain how to properly identify all transitions throughout the of the workers career. Finally, we document the main characteristics of the individuals included in the last available wave, the one for the year 2007.

JEL classification: J60, J80.