100 broiler chickens were divided into 5 groups: the birds 1-20 formed the control group, the birds 21-40 obtained 0.2 % ground caraway, the birds 41-60 0.4 %, the birds 61-80 0.8 % and the birds 81-100 obtained 2 % ground caraway with the food. In the plasma samples that were acquired by slaughtering, the measurement results of the mean values of the concentrations of limonene of all four groups are located in the region of the limit of determination (= 3-4 ng/g), thus resulting in a larger error so that the lower concentrations of limonene at a concentration of 0.8 % and 2 % caraway should not be overrated. The limit of determination of the concentration of carvone lies at 4-5 ng/g, so the calculated mean values are all located above. In the plasma samples that were obtained 2-3 days after stopping to feed the caraway supplement, the concentrations of limonene and carvone were around the limit of determination or even below. The mean concentrations of carvone and limonene in the content of the jejunum obviously show an increase correlating with the ascending concentration of caraway in the feed, both referring to the wet mass and to the dry mass of the jejunum content. The variation of the mean values enlarges with increasing concentration of caraway added to the food. Despite of various concentrations of fed caraway the mean values of the concentration of limonene are nearly the same in all groups in the contents of the caecum, but below the limit of determination (0,05-0,1 µg/g). The variation is especially high in the group that obtained 0.4 % ground caraway. The mean values of the concentration of carvone increase with augmented concentrations of caraway.