MDI may refer to:
Computer science Media Delivery Index, a metric used in IPTV networks Medium-dependent interface (MDI) and medium-dependent interface crossover (MDI-X), types of Ethernet port connections Microsoft Document Imaging Format, a proprietary file format Mission Data Interface, an interface developed by NUWC Keyport Multiple-document interface, a type of software application interface Multi-Draw Indirect, a rendering technique Mean decrease in impurity feature importance (machine learning)
Health Major Depression Inventory, a self-report mood inventory developed by the World Health Organization Metered-dose inhaler, a device that helps deliver a specific amount of medication to the lungs Multiple drug intake, an unnatural cause of death Multiple Daily Injections, a technique of intensive insulinotherapy Mental Development Index, a measure of the cognitive abilities of infants and part of the Bayley Scales of Infant Development
Organizations Management Development Institute, a business school in Gurgaon, India Merchants Distributors, Inc., a wholesale grocery store distributor based in Hickory, North Carolina Movement for Democracy and Independence, a former political party in the Central African Republic Motor Development International, a compressed air car maker
Other uses Mount Desert Island, an island off the coast of the U.S. state of Maine Methylene diphenyl diisocyanate, a chemical Michelson Doppler Imager, an instrument on board the SOHO spacecraft 1501, in Roman numerals Medically determinable impairment, a factor in establishing disability under Social Security Disability Insurance and Supplemental Security Income
See also MD1 Ministry of Defence 1, a British weapon research and development organisation of the Second World War