Background:
NAFTA was the most expansive agreement of its kind when it came into force in 1994. Contemporary trade negotiations grapple with how to deal with tobacco, but there is limited assessment of industry influence of past agreements and how adopted measures have impacted tobacco control.

Methods:
We reviewed internal documents dating from the 1980s to understand the industry's influence of NAFTA negotiations and implementation. We also analysed transnational tobacco companies' (TTCs) business strategies among NAFTA countries before and after the agreement using secondary sources, news articles, industry reports and policy documents. We compiled trade data using the UN Comtrade Database and Trade Map Databases. Data was organized by date and company, and iteratively reviewed to build a narrative related to the tobacco industry and NAFTA.

Results:
TTCs actively lobbied policymakers to include tobacco under NAFTA and specific provisions related to taxation, rules of origin and tariff rate quotas. The industry publicly argued that NAFTA would yield economic benefits to the US and Canada by increasing exports and employment. Privately, TTCs were planning to restructure operations on a North American scale towards a regional business strategy. This strategy was then pursued once NAFTA came into effect, resulting in large-scale decline of US and Canadian operations, and buying up of Mexican companies. TTCs consequently realised greater economies of scale, cheaper inputs and new market access.

Conclusions:
The tobacco industry has supported the inclusion of tobacco under trade and investment agreements on the grounds of economic benefits to signatory countries. NAFTA suggests the industry supports agreements to further regional and global business strategies. Far from serving the interests of local farmers and workers, NAFTA further enabled tobacco industry globalization. The findings provide evidence of the need to protect trade negotiations from industry influence, and reject industry efforts to leverage public health protections for promised economic gains.