Searches for Heavy Quarks at the ATLAS experiment

During 2011 the ATLAS experiment at CERN collected around 5\ifb of proton-proton collision data from the LHC at the center-of-mass energy of $\sqrt{s}=7~$TeV. At such high energy frontier it is possible to explore possible new physics scenarios. Amongst the models of physics beyond the Standard Model (SM) some predict the existence of exotic heavy quarks, which would help explain matter-antimatter asymmetry and solve the hierarchy problem. Several analyses at ATLAS were performed to search for a chiral 4th generation of quarks with charge +2/3 and -1/3 ($t'$ and $b'$ respectively) and for vector-like quarks of different nature. The recent discovery of an Higgs-like, SM-like boson with mass of $\sim 125~$GeV makes the vector-like quark scenario the most interesting one. The status of these searches and the limits set at 95\% C.L. are presented.