Methyl pentanoic acid esters corresponding to the formula ##STR1## wherein R is an olefinically unsaturated, straight-chain or branched-chain or carbocyclic hydrocarbon group, a phenyl or alkyl substituted phenyl group, a phenyl substituted alkyl group, or a phenyl substituted alkenyl group, wherein R contains from 3 to 9 carbon atoms, are valuable perfumes having strong, generally vegetably odor notes and outstanding persistence. They are produced by esterifying 2-methyl pentanoic acid with an unsaturated or carbocyclic alcohol or phenol containing radicals R corresponding to the general formula.The compounds can be effectively combined with other perfumes and standard perfume ingredients to form new compositions. The methyl pentanoic acid ester content thereof generally amounts to between about 1 and about 50% by weight.