An inductively coupled plasma-optical emission spectrometry (ICP-OES) method for the determination of aluminum in baby formula was developed. The sample was digested by microwave digestion and analyzed by ICP-OES. Quantitation was performed using an external standard method. The detection limit was 0.5 mg/kg for 0.5 g of the sample digested and diluted to 25 mL. Linear relationship between emission intensity and aluminum concentration in the range of 0.01 to 50.0 μg/mL was found with a correlation coefficient (r) of 0.999 5. Average recoveries of spiked samples were between 92.2% and 107.0% with relative standard deviations (RSDs) varying from 1.43% to 2.34%. The proposed method permits efficient and accurate determination of aluminum in baby formula with wide linear range, low detection limit, good precision and high recovery and good repeatability.