  The tau is the only known lepton that can decay hadronically. From this class
of decays, high precision measurements of several quantities can be extracted:
the CKM matrix element $V_{us}$, the mass of the strange quark, etc. Also, as a
result of its large variety of decay channels, the study of the tau lepton
represents an interesting tool to search for CP violation and other new physics
effects. In this work, a spin-0 unparticle is considered and its contributions
to the electromagnetic and weak properties of the tau lepton are calculated. It
is found that such contributions can be greater than the standard model (SM)
contributions, though they can be of similar order of magnitude than the
contributions from other SM extensions, such as an extension of the minimal
supersymmetric standard model with vectorlike multiplets. For the unparticles
parameters, the most recent CMS bound from mono-jet production plus missing
transverse energy at the LHC are considered.
