<p>Alumina (Al₂O₃) added to the cryolite (Na₃AlF₆) melt in an electrolysis bath to produce metallic aluminum often partially remains in the melt and leads to an increase in energy costs. Therefore, monitoring the aluminum oxide content in cryolite is an important analytical task in aluminum production. The present paper proposed using bands of the aluminum monoxide AlO green system to estimate the alumina content in cryolites using laser-induced breakdown spectroscopy. For this, a series of samples of the NaF–Na₃AlF₆–Al₂O₃ system with a constant cryolite ratio (1.7) were used. It was found that focusing the radiation below the sample surface by a depth of 3–6 mm provided the minimum RSDs (4–8% for the 0–0 band and 6–10% for the 1–1 band) and the maximum signal-tobackground ratio (80–120 for the 0–0 band and 40–75 for the 1–1 band) in the time window of 4–16 μs after the laser pulse. The selected focusing and time window conditions made it possible to detect a dependence between the intensities of the 0–0 and 1–1 bands of AlO and the alumina content, which was characterized by a high background and relatively low sensitivity. Normalization to the background allowed this dependence to be used for qualitative separation of cryolite systems with high and low alumina contents.</p>