A millimeter-sized ThCr2Si2-type CeNi2As2 single crystal was synthesized by the NaAs flux method and its physical properties were investigated by magnetization, transport, and specific-heat measurements. In contrast to the previously reported CaBe2Ge2-type CeNi2As2, the ThCr2Si2-type CeNi2As2 is a highly anisotropic uniaxial antiferromagnet with the transition temperature TN = 4.8 K. A magnetic-field-induced spin-flop transition was seen below TN when the applied B is parallel to the c axis, the magnetic easy axis, together with a huge frustration parameter f = θW/TN. A pronounced Schottky-type anomaly in specific heat was also found around 160 K, which could be attributed to the crystalline electric field effect with the excitation energies being fitted to ▵ 1 = 325 K and ▵ 2 = 520 K, respectively. Moreover, the in-plane resistivity anisotropy and low-temperature x-ray diffractions suggest that this compound is a rare example exhibiting a possible structure distortion induced by the 4f-electron magnetic frustration. [ABSTRACT FROM AUTHOR]