Objectives: The literature presented first evidence that the concentration of opiate alka-loids present in poppy seed intended for use in food may be reduced during food processing. Those influencing factors were not considered in forensic studies about the interaction between poppy seed food and tests for drugs-of-abuse. In the majority of studies the ingested product was not analysed but only the poppy seed that was originally used for the production of the particular product. The seed concentration was then used to calculate the putative amount in the ingested product. Because of the manifold possibilities for morphine reduction during food processing, the ingested morphine dosage was therefore overestimated. This may also be an explanation for the unsuccessful correlation between ingested dosage and concentration in blood or urine that was found in a number of studies. Methods: Typical food processing steps (e.g. grinding, baking, washing, drying) were systematically studied using statistically designed experiments. The analysis was conducted using a validated LC/MS/MS procedure. Results: A significant change of the morphine concentration of poppy seed food during typical processing steps was detected. Grinding of the poppy seed leads to a morphine reduction of approximately 34%. The degradation occurs directly at grinding and does not continue during subsequent storage. Baking of poppy cake reduces morphine up to 84%. The production of poppy buns is known for losses of up to 90%. Washing the poppy seed with hot water (60°C) is an effec-tive way to reduce the morphine content by approx. 70%. The optimal treatment of poppy seed consists of washing, drying, and grinding. This process significantly reduces the morphine content and simultaneously improves the organoleptical quality of the product. Discussion: For adequate interpretation of forensic studies about consumption of poppy seed food, the analysis of the ready-to-eat food using a suitable method must be demanded. Only in this manner, the ingested amount of morphine is known and correlations may be established. The studies should be conducted using realistic amounts of ingestion, authentic recipes and pla-cebo controls to assess the real risk potential of poppy seed food.