That alkali treatments can improve the nutritional quality of poor quality roughages has long been established (Sundstol and Owen, 1984). However, their effectiveness is limited by their potential hazards to the animals and mankind. Alkaline hydrogen peroxide (AHP) has recently emerged as a possible substitute (Gould, 1985) but its farm scale application is limited by the need for high amounts of chemicals and water. Lack of any information regarding its effectiveness over NaOH alone is another factor which requires further investigation. The present study was, therefore, planned to assess the effectiveness of pH-regulated (11.5±0.2) H2O2 (AHP) in improving the in vitro dry matter digestibility (IVDMD) of wheat straw (WS, Avalon) under different laboratory conditions. The possibility of using CaO on its own or to regulate pH for AHP was also tested.