We have measured the resistivity of antiferromagnetic Ce0.8La0.2(Ru0.85Rh0.15)(2)Si-2 along the tetragonal c-axis under various hydrostatic pressures. At P = 0 GPa we observe no gap-type jump in the resistivity at T-N as has been observed for Ce(Ru0.85Rh0.15)(2)Si-2 at the spin density-wave (SDW) transition temperature, but rather downward bend with decreasing temperature. At P >= 0.48GPa we observe the gap-type jump just below TN. These facts suggest the recovery of the gap opening due to the Fermi-surface nesting by pressure from a conventional localized antiferromagnetic state. (c) 2005 Elsevier B.V. All rights reserved.