A simple method was developed for the determination of sterigmatocystin in infant cereals. The method consists of a quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction approach and cleanup with an SPE HLB cartridge. After purification for separation and quantification of sterigmatocystin, HPLC with UV detection and diode-array detection (DAD) was used at sterigmatocystin levels >10 μg/kg, whereas ultra-performance LC with electrospray ionization (ESI) and tandem MS (MS/MS) was used at levels <10 μg/kg. The compound was determined by UV-DAD at 325 nm and by ESI-MS/MS in the positive ionization mode. Good r(2) values (≥0.99) were found with both UV-DAD and ESI-MS/MS, and satisfactory recoveries (84.8-96.2%) of sterigmatocystin in infant cereals were demonstrated, with RSD values ≤11.43%. The developed analytical method was used for the determination of sterigmatocystin in infant cereals from Hangzhou, China.