Sago bark is generated as by-product from sago starch industries. Malaysia as one of the biggest exporter of sago starch produces a lot of sago bark wastes which are now burned on-site and underutilized. This study aims to apply subcritical water as a green solvent for hydrolysis of sago bark in order to obtain the value-added products. Inner and outer layers of sago bark were subjected to subcritical water treatment at 180 °C to 320 °C for 5 minutes. Inner layer showed higher yield of total organic carbon and total sugar at 210 °C than the outer layer, 0.40 and 0.67 g/g-dry sample respectively. Both layers had generated similar types of monosaccharides and inner layer showed extremely better yield of glucose, xylose and arabinose with the value of 0.125, 0.123 and 0.019 g/g-dry SB, respectively. Six organic acids were identified and were most favored to produce at a higher temperature. The increasing temperature had led to an apparent tar yields, ~0.40 g/g-dry SB and a huge drop of solid residues, ≥75%. In general, the inner layer was more susceptible to subcritical water treatment than the outer layer with evident yields of all products produced.