Cornwall is a port-of-entry into Canada, and is connected to Massena, New York, USA via the Seaway International Bridge.

The economy has had its ups and downs since the 1980s. The city was rocked with a recession in the early 1990's. Most recently the city's long time industrial leader, Domtar, closed operations.

With the economic downturn, many of Cornwall's urban problems have become much more pronounced. A serious drug/IV problem in the troubled east end of the city has caused the provincial government to open a methadone clinic near the heart of the infected neighbourhood.

The area is also home to the Akwesasne (Mohawk Indian) reservation which recently has been linked to massive smuggling operations across the U.S./Canada border. The level of illegal activity in the area has also led to the proliferation of many organized crime organizations in and around the city. High levels of trafficking of illegal materials, drugs, and cigarettes led the RCMP to locate a large district operation in the city in 2005.

Cornwall has one of the highest murder rates in the nation on a per-capita basis. With five homicides in 2004 and four homicides in 2005, Cornwall's murder rate per capita is 11.3 per 100,000 people. For comparison, Toronto had 78 murders in 2005 for a murder rate per capita of 3.1 per 100,000 people.