Summary. Uptake, distribution and fate simazine (2‐chioro‐4,6‐biserthylamino‐s‐triazine) in 4‐year‐old seedlings of Norway spruce (Picea abies) are discussed. Simazine was found to be readily absorbed and distributed in the spruce seedlings. A positive relationship between the amount of simazine absorbed and the growth intensities of the plants indicates an active mechanism of uptake. A fixation of simazine in roots and sterm was observed. Simazine was degraded by roots and stem to hydroxysimazine and two other unknown metabolites. No simazine and only metabolites could be traced in the needles, indicating a very rapid rate of metabolism in the root system. The glucose derivative of benzoxazinone was extracted from all parts of the spruce seedlings and is probably responsible for the hydrolysis of simazine. The results indicate a very slow degradation of the metabolites to CO2 as one of the final products. Copyright © 1969, Wiley Blackwell. All rights reserved