The amount of C14-labeled triazine herbicides absorbed by the upper and lower surfaces of peanut (Arachis hypogea) leaves was found to be significant with the exception of 2-methoxy-4,6-bis(isopropylamino)-s-triazine (prometone). Almost always a surface active agent increased the absorption of triazine herbicides by the leaves. The surface active agent did not play any role in diffusion of these herbicides. Among the four herbicides tested 2-chloro-4-ethylamino-6-isopropylamino-s-triazine (atrazine) and 2-methoxy-4,6-bis(isopropylamino)-s-triazine (prometone) were found to move both acropetally and basipetally, whereas 2-chloro-4,6-bis(ethylamino)-s-triazine (simazine) and 2-chloro-4,6-bis(isopropylamino)-s-triazine (propazine) moved only in the acropetal direction.