The compound gamma-butyrolactone (GBL) was found in extracts from samples of unadulterated wines. This finding indicates that GBL is a naturally occurring component in some wines and may be present in similar products. The concentration detected was approximately 5 µg/mL and was easily observed using a simple extraction technique followed by GC/MS analysis. These results illustrate the need to carefully examine an allegedly adulterated sample's matrix before determining a sample was laced with GBL.