Paving block is a building material made of cement, water, and fine aggregate used as an alternative cover or hardening for land surface. It is commonly used for various purposes such as, sidewalks, parking lots, and road pavement. The increasing demand of cement-forming materials is due to the rise in the number of cement users, therefore, an environmentally friendly material is needed to be produced from industrial waste. Generally, Indonesia has extensive oil palm plantations, as a result, excess wastes are produced from the burning of oil palm shells namely, boiler scale ash (contains silica oxides (SiO 2 ), pozzolan, and other compounds present in cement). Smelting and metal refining industries produce wastes from Granulated Blast Furnace Slag (GBFS), which contains silica oxide as their major chemical composition. Therefore, this study aims to determine the compressive strength and the water absorbing capacity of paving blocks using 10% of Palm Boiler Crust Ash as a substitute for fine aggregate/sand, and the percentage variations of Granulated Blast Furnace Slag (GBFS) waste as a cement replacement material. The results showed that the paving block variation V 2 had the highest compressive strength (22.83 MPa), while the highest water absorption (5.45%) was found in variation V 1 , which was higher than the normal paving block (2.39%).