İzmit is an important industrial centre, with a large oil refinery, and major paper and cement factories. Ford Motor Company has a plant here in a joint venture with Otosan, assembling the Transit/Tourneo and Transit/Tourneo Connect vans. It is also a transportation hub, being located on the main highway and railway lines between İstanbul and Ankara, and having a major port.
In the past few years the province has developed into a growth point for the automotive industry, receiving investment from Ford, Hyundai, Honda and Isuzu. Tyre and rubber products are produced to world class standard (Goodyear, Pirelli, Lassa and Bridgestone). Today Kocaeli province has grown 1200 industrial investments of which 108 have been established with international capital. Turkeys largest enterprise, Tüpraş Petroleum Refinery Plant, is also located in Kocaeli, containing altogether 27% of the national chemical industry (petro-chemical included), including 18 of the 100 largest enterprises of Turkey are located in Kocaeli and paying 17-18% of the national tax revenues.
Financial Times affiliated Foreign Direct Investment Magazine nominated Kocaeli (the province of which İzmit is the capital) among the 25 European Regions of the Future for 2006-2007. The city was chosen along with Adana for Turkey, which scored the most points for cost effectiveness against Kocaeli's wider infrastructure, while Adana and Kocaeli tied on points for human resources and quality of life.
The famous Turkish traditional sweet Pişmaniye is a product of İzmit and the Kocaeli Province.