The invention comprises substituted ureas of the general formula <FORM:1033262/C2/1> wherein R is selected from phenyl, halogen substituted phenyl, C1 to C6 alkyl or alkoxy substituted phenyls, halogen and C1 to C6 alkyl substituted phenyls, phenoxy, halogen substituted phenoxies, halogen and C1 to C6 alkyl substituted phenoxies, nitro substituted phenoxies, halogen and nitro substituted phenoxies, C1 to C6 alkyl substituted phenoxies, naphthyl and naphthoxy; R1111 is hydrogen or C1 to C6 alkyl; R1 is hydrogen, C1 to C6 alkyl, C1 to C6 alkoxy, phenyl, C1 to C6 alkyl substituted phenyl, halogen substituted phenyl, C1 to C6 alkyl and halogen substituted phenyl, C1 to C6 alkoxy substituted phenyl, C1 to C6 alkoxy and halogen substituted phenyl, nitro substituted phenyl, nitro and C1 to C6 alkyl substituted phenyl, nitro and halogen substituted phenyl, nitro and C1 to C6 alkoxy substituted phenyl, or naphthyl; R11 and R111 are radicals selected from the radicals R1 and <FORM:1033262/C2/2> n is 1, 2 or 3 and at least one of the radicals R1, R11 and R111 are other than hydrogen. These ureas may be prepared by heating phosgene or a carbamyl halide at 60 DEG  to 132 DEG  C with an aryl acyl amide or an aryloxy acyl amide, in which the hydrogen atom bonded to the nitrogen atom is possibly substituted by an organic hydrocarbon radical.  Alternatively, they may be prepared by the action at 60 DEG  to 132 DEG  C. of the chloride of an aryl-acylated acid or of an aryloxy-acylated acid or a urea which is possibly substituted but still contains at least one hydrogen atom or at least one of the nitrogen atoms. The compounds of the invention are herbicidally active (see Division A5).ALSO:Herbicidal compositions comprise at least one substituted urea of the general formula <FORM:1033262/A5-A6/1> wherein R is selected from phenyl, halogen substituted phenyls, C1 to C6 alkyl or alkoxy substituted phenyls, halogen and C1 to C6 alkyl substituted phenyls, phenoxy, halogen substituted phenoxies, halogen and C1 to C6 alkyl substitued phenoxies, nitro substituted phenoxies, halogen and nitro substituted phenoxies, C1 to C6 alkyl substituted phenoxies, naphthyl and naphthoxy; R1111 is hydrogen or C1 to C6 alkyl; R1 is hydrogen C1 to C6 alkyl, C1 to C6 alkoxy, phenyl C1 to C6 alkyl substituted phenyl, halogen substituted phenyl, C1 to C6 alkyl and halogen substituted phenyl, C1 to C6 alkoxy substituted phenyl, C1 to C6 alkoxy and halogen substituted phenyl, nitro substitued phenyl, nitro and C1 to C6 alkyl substituted phenyl, nitro and halogen substitued phenyl, nitro and C1 to C6 alkoxy substituted phenyl, or naphthyl; R11 and R111 are radicals selected from R1 and <FORM:1033262/A5-A6/2> n is 1, 2 or 3 and at least one of R1, R11 and R111 are other than hydrogen, together with an inert carrier or diluent.  Specified forms of compositions are solutions in organic solvents, aqueous emulsions, aqueous and/or organic suspensions, powders, granules and tablets. The compositions may also comprise adjuvants, e.g. alkali chlorides, creosote, phenols, kerosene, gas oil and fuel oils, and known herbicides, e.g. nitrated phenols; chlorinated nitrated phenols; aryloxyalkyl carboxylic acids halogenated on the nucleus; polyhalogenated benzoic, alkylcarboxylic or phenyl-alkyl-carboxylic acids or their salts, esters, amides or imides; monohalogenated or polyhalogenated thiolcarbamates, thiocarbamates or carbamates; monosubstituted or disubstituted amides; monosubstituted or polysubstituted ureas possibly containing halogen atoms; substituted triazines; hydrazides; quaternary ammonium compounds; bichromates; chlorates; borates; or alkali cyanates.  Examples relate to the use of a wettable powder, containing a substituted urea of the invention together with kaolin, a product based on bisulphite cellulose and a product based on sodium alkylaryl sulphonate, and a solution emulsifiable in water, containing a substituted urea of the invention, a polyethoxylated derivature of alkyl phenol and amine alkylaryl sulphonate and cyclohexanone.