Concrete is a composite material (mixture) of several materials, the main material consists of a mixture of cement, fine aggregate, coarse aggregate, and water, or without other additives, in a specific ratio. Using iron lathe waste as an additive and as a fiber in concrete is a solution to reduce the amount of waste/garbage generated from the iron lathe industry. In addition, this waste is also cheap and environmentally friendly. This research aims to determine the effect of iron lathe waste addition on the compressive strength of 25 MPa concrete. This was experimental research conducted by adding iron lathe waste with variations of 0%, 12.5%, 15%, and 17.5% of the cement weight. The test object used was a cylinder with a diameter of 15 cm x 30 cm. It was tested at 28 days, and the planned compressive strength was 25 MPa. The research results indicated that the average compressive strength using iron lathe waste as an added material with variations of 0%, 12.5%, 15%, and 17.5% were 26.89 MPa, 25.48 MPa, 23.87 MPa, and 22.65 MPa, respectively, therefore it can be concluded that the higher the percentage of addition of iron lathe waste, the lower the compressive strength of the concrete.