Naturally occurring hormones in manure from livestock may cause negative<br/>environmental effects, if they are released into natural waters. Estrogens in very low concentrations (ng L–1) may affect the endocrine system of fish and amphibians. Elevated levels of estrogens have been found in surface waters in areas of intensive manure application. To investigate if leaching through the soil profile is a significant transport mechanism for estrogens in slurry we conducted leaching experiments on intact soil. Undisturbed soil monoliths (60 cm diameter, 100 cm long) from two sites in Denmark (one loamy and one sandy soil) were amended with pig slurry spiked with a reactive tracer (17α-ethynylestradiol (EE2)) and a conservative tracer (bromide). The monoliths were exposed to (i) a short-term irrigation event and (ii) a natural precipitation long-term semi-field experiment. We found that natural estrogens in the slurry could be transported to one meters depth in both the loamy and the sandy soil. The concentrations observed could affect the endocrine system of aquatic wildlife. A higher percentage of the natural estrogens added to the monoliths was leached compared to the EE2. This indicates a higher mobility of the naturally occurring estrogens compared to a reactive tracer with similar transport characteristics (EE2).