In this paper the administrative data of the "Employment centres" (CPI) are used to analyse some structural features of the local labour markets (LLMs) of Umbria and to investigate their interaction dynamics. In the first part of the paper the major contributions available in the literature about LLMs are reviewed and the adoption of the Local Labour Systems as the proper analytical unit of reference is discussed and explained. Then, the transition matrixes (2000-2002) are used to estimate the probability of permanence and transition of labour demand and supply and to investigate their macro, and microeconomic determinants. More particularly, the propensity to territorial mobility of labour supply is assessed with regards to individual features of workers (gender, age, education), and the importance of different contractual options. The outcomes shed light on the effective articulation of Umbria into LLMs, and show a higher propensity to territorial mobility for men and higher educated workers. They also show that LLMs where temporary contracts are more diffused mean higher permanence probabilities for women.