Conversion of pulp mill sludge into activated carbon is an alternative solution for waste management at pulp mills. In this study, the use of white liquor as an activating agent was investigated, with the aim of applying an available source at pulp mills. A Specific Surface Area (SSA) value of 650m(2)/g and an activation yield of 61 % were achieved with synthetic white liquor at 600 degrees C and 2h. The SSA values obtained with white liquor were approximate to 60 % lower than those with NaOH alone. Thermodynamic analyses, X-ray diffraction, and elemental analyses showed that both Na2S and Na2CO3 inhibit the activation reaction with carbon.