Abstract: In this study, various oil industrial wastes such as spent filtration earth (SFE), spent bleaching earth (SBE), sludge from oil refining industry (SOI) or sludge from pomace oil extraction industry (SPOEI) were used as secondary raw material for the manufacture of clay bricks. The clay and waste were characterized by X-ray diffraction, X-ray fluorescence, and thermogravimetric, differential thermal, and chemical elemental analysis. The bricks were manufactured from clay and the optimal proportion of waste (10 wt %). The influence of the waste addition on the linear shrinkage, bulk density, water absorption, and mechanical and thermal properties was investigated. The spent bleaching earth or sludge from oil industry addition produced a water absorption increased to above 25%, the compressive strength decreased between 24 and 39 % and the thermal conductivity decreased between 18 and 25%, respectively. The incorporation of sludge from pomace oil extraction industry or spent filtration earth of clay was more beneficial, with compressive strength values similar to bricks without waste and a 6 and 14% improvement in thermal conductivity, respectively. Water absorption and the SEM micrographs indicated that the changes in the results were due to the type of porosity formed by the type of waste.