Three white poppy seed samples of Papaver somniferum L were found to contain total morphine (free and bound) in the range 58.4 to 62.2 micrograms/g seeds and total codeine (free and bound) in the range 28.4 to 54.1 micrograms/g seeds. Soaking seeds in water was found to remove 45.6 per cent of the free morphine and 48.4 per cent of the free codeine. In ingesting a curry meal or two containing various amounts of washed seeds (morphine intake: 200.4 to 1002 micrograms; codeine intake: 95.9 to 479.5 micrograms), the urinary morphine levels were found to be in the range 0.12 to 1.27 micrograms/ml urine and urinary codeine levels in the range 0.04 to 0.73 micrograms/ml urine. In any large scale screening for abuse of opiate drugs, the possibility of urinary alkaloids arising from consuming food containing poppy seeds must be considered and, if possible, eliminated.