Tau Physics at CMS

At the LHC, $\tau$-leptons are frequently produced in the decays of W and Z bosons. The development of an efficient and accurate reconstruction and identification of $\tau$-leptons is therefore an important item in the CMS physics program. However, this is challenging due to neutrino in the final state. We report on the development of algorithms to identify $\tau$-lepton decays and discuss the first CMS measurements of W and Z decays involving $\tau$-leptons using the 7 TeV dataset from the pp-run in 2010.