RCCSD(T) calculations combined with large basis sets are employed to obtain the heats of formation and dissociation energies of NaOH and NaOH+. Our best values are DeltaH(f)(NaOH,0 K) = -44 +/- 1 kcal mol(-1) and D-0 = 79 +/- 1 kcal mol(-1). The ground state of NaOH+ is a X(2)Pi state, which is split by a very small Renner-Teller interaction. We calculate AIE (NaOH) = 7.87 +/- 0.05 eV, DeltaH(f)(NaOH+,0 K) = 137 +/- 1 kcal mol(-1), and D-0 = 16 +/- 1 kcal mol(-1). The proton affinity of NaO(X(2)Pi) is derived as 250 +/- 1 kcal mol(-1). In addition, we conclude that, experimentally, the Vibrational frequencies of neither NaOH nor NaOH+ are known with any reliability.