The paper presents the results of studies of the possibility of utilization of petroleum sludge, obtained during the purification of oil-water emulsions, using gabbro-diabase powder in the production of ceramic building products. The sludge is proposed to add to the clay mass as an entrained additive. The influence of the sludge additive mass on such physical and mechanical indicators of ceramic samples, as density, compressive strength, water absorption, air shrinkage and fire shrinkage, and density, is studied. Ceramic samples were prepared using natural clays, deposits Bessonovka (Belgorod region) and Podgornoye (Voronezh region). It is shown that the addition of 2% mass to the clay mass of the sludge leads to an increase in the compressive strength of the samples up to 90%, an air shrinkage of 1%, an increase in water absorption 1-2%. The value of the fire shrinkage remains unchanged. With an increase in the proportion of sludge additive to 7%, all indicators slightly change. Water absorption and air shrinkage increase, compressive strength, fire shrinkage and density decrease. However, further, when there is 7% of sludge in the clay mixture, the strength of ceramic samples corresponds to a grade not lower than 150, according to GOST 530-2012.