AbstractThe fibers of oil palm empty fruit bunch (OPEFB) stalks were investigated to determine the changes in their basic properties after oven-heat treatment. The oven-heat treatment was conducted at 100 °C or 190 °C for 15 min. There were slightly noticeable morphological, chemical, and thermal alterations in oven-heat treated OPEFB stalk fibers for short duration. Scanning electron microscopy (SEM) revealed that the treated fibers had smooth surfaces and irregular heavy deposition of cementing agents. The highest cellulose content (41.68%) was present in OPEFB stalk fibers treated at 100 °C for 15 min, whereas the highest crystallinity index (48.74%) occurred in fibers treated at 190 °C for 15 min. The fibers comprised cellulose, lignin, and hemicellulose with a high percentage of C, O, K, and other elements. Based on differential scanning calorimetry (DSC) analysis, oven-heat treated and untreated OPEFB stalk fibers had similar thermal stability characteristics.