Background: A simple, rapid, and efficient liquid chromatography tandem mass spectrometry (LC–MS/MS) method, operated in electrospray ionization (ESI) and quadrupole linear ion trap modes, has been developed for the identification and structural characterization of zearalenone (ZEN) in corn oil. Methods: Samples (5 g) were extracted with acetonitrile/water (80:20, v/v). After centrifugation and dilution, the extracts were separated on a C18 analytical column by gradient elution (acetonitrile/water) and analyzed by UPLC–MS/MS. Enhanced product ion mode was used for qualitative analysis, while multiple reaction monitoring mode was used for quantitative analysis. Results: Calibration curve showed good linearity with correlation coefficients (r) higher than 0.995. Limit of detection was determined to be below 0.20 μg kg-1 for ZEN. The recovery for ZEN was in the acceptable range of 86.6% to 97.2%. 82.4 % of the samples were found to contain ZEN among the 51 samples.Conclusion: The sample pretreatment and LC–MS methods developed in this research, from a convenience and analysis time perspective, are simple, efficient, cheaper, and less time-consuming than existing methods.