Peat soils often suffer from problems such as pH levels that tend to be acidic to very acidic, and low levels of available macronutrients N, P, and K to plants.  Bottom ash and compost have considerable potential to be utilized as additives or ameliorants. The purpose of this study was to determine the effect of applying bottom ash and compost on soil pH and the availability of N-ammonium, phosphorus, and potassium in peat soil. This research used a two-factor completely randomized design. The factors tested were the application of bottom ash and compost; there were eight treatments and one control. The results showed that the combined treatment of bottom ash and organic compost was able to increase N-ammonium, P-available, and K-available in peat soil. The single bottom ash treatment was able to increase the pH value of peat soil. A single bottom ash treatment of 20 t ha-1 (B20) is the best dose that can increase the pH value. The combination of bottom ash 10 t ha-1 + compost 20 t ha-1 (B10K20) is the best dose that can increase N-ammonium. Application of 0 t ha-1 bottom ash + 20 t ha-1 compost (B0K20) is the best dose that can increase available P and K.