Papaver somniferum (opium poppy) is one of the world's oldest medicinal plants which are widely used for medicinal, nutritive and scientific purposes. Turkey is one of the major legal opium poppy producer countries in the world and the seed paste of the poppies is consumed in great deal, even more than 100 g per meal. The main objective of this study is to investigate the influence of poppy seed paste ingestion on urine tests for opiates whether or not could lead to opiate positive urine test results. For this purpose, a variety of poppies were used and the morphine content of white, yellow and blue-black poppies were determined as 1.9, 4.0 and 2.6 mg/kg, respectively. 100g of these seed pastes were consumed in the breakfast by ten healthy adults enrolled in the study over three days and urine samples were collected before and after the breakfast. Opiate screening analysis was carried out by enzyme immunoassay method and the results were evaluated by two different cut-off values (300 and 2000 ng/mL). Morphine confirmation analysis was made by GC-MS system and the chromatographic method was validated in terms of selectivity, extraction efficiency, linearity (25-2000 ng/ml), intra-assay precision, accuracy, limit of detection (LOD) and limit of quantitation (LOQ) (3 and 10 ng/ml), carryover, matrix effect, dilution integrity and stability. According to cut-off value 300 ng/ml, opiate concentrations were found positive up to 48 h. For cut-off value 2000 ng/mL; this time was up to 12 h in collected urine samples after consumption of three different colored poppy seed pastes. In all urine samples, thebaine was detected while the heroin abuse metabolite 6-acetyl morphine (6-AM) was not. Urine drug testing legislation was revised on 2016 in Turkey and opiate screening cut-off values increased from 300 to 2000 ng/mL. Overall results have shown that poppy seed paste as food consumption could lead to opiate positive urine test result even if increased cut off levels are used. It can also be deduced that thebaine can be taken as supportive biomarker for poppy seed paste consumption. Awareness of interpretation of urine test results and defining the procedures especially for forensic drug testing must be done in legal aspect to ensure justice for each individual (workplace, traffic, court etc.). (C) 2018 Published by Elsevier B.V.