Abstract We have carried out 139La NQR measurements on La 2− x Sr x CuO 4, La 1.80CuO 4 and La 2Cu 0.85Ni 0.15O 4 at 1.3 K and 4.2 K in both zero and applied fields. We find from the zero field Zeeman splitting of a NQR peak that La 2− x Sr x CuO 4 remains magnetically ordered up to x=0.05 at low temperatures. Increasing the Sr-doping lowers the NQR frequencies, which is consistent with a decrease of the electric field gradient (EFG) at the La nuclei. The NQR spin-echo decay rate ( 1 T 2 ) increases with a very small amount of Sr-doping ( x=0.01) and shows a peak at x=0.01. The close similarity between the spectra of La 1.80CuO 4 and La 2CuO 4 suggests a lack of simple substitutional La vacancies in the nominally La-deficient sample. Strong broadening of the NQR spectrum in the Ni-doped sample was observed.