Diimide is most effective at reducing unpolarized carbon-carbon double or triple bonds. In reactions with other unsaturated systems, disproportionation of diimide to nitrogen gas and hydrazine is a competing process that significantly degrades the reducing agent. Many groups that are ordinarily sensitive to reductive conditions, including peroxides, are not affected by the conditions of diimide reductions.
Diimide will selectively reduce less substituted double bonds under some conditions. Discrimination between terminal and disubstituted double bonds is often low, however.
Allenes are reduced to the more highly substituted alkene in the presence of diimide, although yields are low.
Iodoalkynes represent an exception to the rule that alkenes cannot be obtained from alkynes. After diimide reduction of iodoalkynes, cis-iodoalkenes may be isolated in good yield.
Recently, diimide has been generated catalytically through the oxidation of hydrazine by a flavin-based organocatalyst. This system selectively reduces terminal double bonds. 
In general, diimide does not efficiently reduce polarized double bonds; however, a limited number of examples do exist in the literature. Aromatic aldehydes are reduced by diimide generated through the decarboxylation of potassium azodicarboxylate.