Maneb (manganese ethylene-bis-dithiocarbamate) is a fungicide and a polymeric complex of manganese with the ethylene bis (dithiocarbamate) anionic ligand.

Exposure to maneb can occur when breathed in; it can irritate the eyes, nose, and throat as well as cause headache, fatigue, nervousness, dizziness, seizures and even unconsciousness. Prolonged or long-term exposure may interfere with the function of the thyroid. Exposure to maneb is also shown to induce a Parkinson's disease like neurotoxicity in mice. It is still challenged whether maneb, along with Paraquat, is an environmental risk factor for Parkinson's disease. In 2022 a review from India stated that "From the studies we can consider that PQ and MB with its combined effects has tremendous contribution towards neurodegeneration in PD."

Manganese(II) ethylenebis(dithiocarbamate) of low ethylenethiourea (ETU) content is prepared by mixing disodium ethylenebis (dithiocarbamate) with formaldehyde in aqueous medium then mixing a water-soluble manganese(II) salt to precipitate the maneb. The product can be further formulated with a metal salt and also with paraformaldehyde. (See External links for the patent citation)

Maneb, is a broad spectrum fungicide that is extensively applied against a wide range of fungal pathogens affecting ornamental plants, food and feed crops. It can also be used to create a toxin-based animal model of Parkinson's disease, usually in primates.

Maneb was included in a pesticide ban proposed by the Swedish Chemicals Agency and approved by the European Parliament on January 13, 2009.