This research studied effect of natural fibers from deposal materials on mechanical properties of cement fiber ceiling boards to explore an appropriate mixture. Natural fibers from paper tissues and oil palm fibers were used as an aggregate mixed with Portland cement type 1. The percentages of paper tissues (P) ranged 25-35, oil palm fiber (F) were 0 and 1 and water cement ratio (W) ranged 0.8-1.4 in total 10 mixtures. The specimens were then proved by testing of compressive strength, flexural strength, modulus of elasticity, thermal property and sound absorption. It was found that an increase in the percentage of paper tissues had a direct consequence in decreasing of compressive strength, flexural strength, and modulus of elasticity. Though, increasing of oil palm fibers showed effect on thermal property. Therefore, there was no remarkable impact on sound absorption. In thermal properties aspect, the suitable mixture was P25F1W90 because it yielded the highest efficiency ventilation. These ceiling boards not only help to reduce energy consumption in buildings but also can be a choice to make effective use of waste materials that can be an alternative for low-cost construction.