CeNiGe2 crystallizes in the orthorhombic CeNiSi2-type layered structure and exhibits large magnetic and transport anisotropy. The compound undergoes two antiferromagnetic transitions at TN=4 K and TM=3 K. We report measurement of the electrical resistivity on a CeNiGe2 single crystal as a function of the temperature and magnetic field (i || b axis, H ⊥ b axis) performed under hydrostatic pressure up to 9 kbar. Upon application of magnetic field, antiferromagnetic transitions merge into a single transition and this transition is completely suppressed in fields greater than 5 T. Application of pressure causes a reduction of the ordering temperatures. The results are compared with findings for other Ce compounds and discussed in terms of moment instability and the variation of exchange due to increased 4f-ligand hybridization. © 2003 American Institute of Physics.