We report here the magnetic susceptibility, specific heat and electrical resistivity on high-quality single crystals of YbIr 2Si 2. It crystallizes either in the I-type body-centered ThCr 2Si 2 or P-type CaBe 2Ge 2 structure. P-type sample orders magnetically below 0.7 K whereas the I-type system remains paramagnetic down to 40 mK and shows heavy fermion behavior. Low-temperature resistivity and specific heat of this compound has strong similarity with YbRh 2Si 2 down to 400 mK. However, below 200 mK YbIr 2Si 2 attains Fermi-liquid ground state in contrast to YbRh 2Si 2 which shows non-Fermi-liquid behavior.