Gas hold-up (epsilon(G)) in air-aqueous electrolyte solutions in stirred tank reactors (STR) is correlated using a relative gas dispersion parameter, N/N-cd and a surface tension factor (STF), (c/z)(dsigma/dc)(2). For electrolyte concentration below transition concentration (c(t)) a single correlation in the form of epsilon(G) = f(N/N-cd, vvm, STF) shows good agreement with gas hold-up data over a wide range of system and operating conditions. Above c(t) no effect of STF on gas hold-up is, observed, and the correlation obtained is of the form epsilon(G) = f(N/N-cd, vvm). Data available in the literature on large STR show good fit with the proposed correlation.