It is located on the northern central coast of Santa Catarina and is part of the Vale do Itajaí Mesoregion, on the right bank of the Itajaí-Açu river mouth.

The city has the 2nd largest gross domestic product[3] and the highest per capita income in the State of Santa Catarina.

The city was founded on June 15, 1860, but the colonization of Itajaí had started in 1658 when the Paulista João Dias D'Arzão arrived in the region.

[citation needed] Itajaí and most of Santa Catarina State area is prone to torrential storms specially during the Spring season.

[citation needed] In late November 2008, around 100 people perished in floods due to the long lasting showers that fell in Southeastern and Southern Brazil.

[4] Many lost their homes and other possessions and had no ready shelters to turn to, for the rain combined with river waters invaded every section of the city and most of Central and Coastal Santa Catarina State.

It serves as the main port for exports in the region, and almost all production of the state of Santa Catarina moves through it at some point.

[citation needed] Itajaí has a píer for passenger vessels, serving the coast of Santa Catarina and used by the customs, which guides ships in by laser.

Itajaí is also the hub of Nautical Club Marcílio Dias, a sport association for both football (soccer) and competitive rowing.

The city is served by Ministro Victor Konder International Airport located in the adjoining municipality of Navegantes.