Overview of PbWO4 calorimeter in CMS

The status is given of the lead tungstate (PbWO4) electromagnetic crystal calorimeter for the CMS detector at LHC. This includes the progress on the engineering design of the calorimeter and its readout system, latest results on PbWO4 crystals and photodetector development, with particular attention to radiation hardness issues, and results from test measurements in particle beams.