The mycotoxin test data base (2005–2009) of the Veterinary PublicHealth Laboratory (VPHL), Department of Veterinary Services, Malaysia (DVS) showed that there was a significant increase (51%) of overall aflatoxin occurrences in various types of animal feed samples, especially those formulated from agricultural by-product, for the year 2008. A study was thus conducted to investigate if there could be some sources of mycotoxin contamination during theperiod of sample handling. Three different laboratory storage conditions were chosen for the study within a period of fourteendays i.e 4 °C, room temperature (in light) with mean relative humidity of 62.5%, and room temperature (in dark) with mean relative humidity of 55.7%. The observations showed that there were nosignificant differences in total aflatoxin, zearalenone, and fumonisin detections in all storage conditions as screened by the ELISA technique. However 11– 50% inconsistencies of the mycotoxinconcentrations detected were observed within the samples.