Abstract: The present invention relates to phenyluracils of formula (I) or their agriculturally acceptable salts or derivatives, wherein the variables are defined according to the description, processes and intermediates for preparing the phenyluracils of the formula (I), and their use as herbicides, i.e. for controlling harmful plants, and also a method for controlling unwanted vegetation which comprises allowing a herbicidal effective amount of at least one phenyluracil of the formula (I) to act on plants, their seed and/or their habitat.