I aprile 2003 - Dott. V. Ripepi Pulsating Pre-Main-Sequence stars: Theory vs Observations ABSTRACTe-Main-Seque A relatively new and rather unexplored class of variable stars is represented by the PMS $\delta$ Scuti stars. The number of these pulsators has rapidly increased during the last few years, also thanks to our theoretical and observational efforts. I will briefly review the status of the art for these objects, and present recent results obtained by our group. The comparison between theory and observations is used to derive information on the distance and intrinsic stellar parameters. Future developements are briefly discussed. webmaster - Aprile 2003