Borja-Bravo, M., García-Salazar, J. A. and Skaggs, R. K. 2013. Mexican fresh tomato exports in the North American market: A case study of the effects of productivity on competitiveness. Can. J. Plant Sci. 93: 839-850. The North American market for fresh tomatoes (Lycopersicon escolentum Mill.) involves a complicated web of bilateral trading relationships between the United States, Mexico and Canada. Trade in fresh tomatoes between the three countries has changed significantly in recent years. In particular, Mexico's share of total US fresh tomato imports from all countries decreased from 93 to 88%, while Canada's share of US fresh tomato imports increased from 3 to 11% between 1996 and 2009. Mexico's declining competitive position in the US fresh tomato market is also evidenced by the fact that the Mexican share of combined Mexico-Canada exports to the United States decreased from 97% to 89% between 1996 and 2009. A spatial and inter-temporal model was used to analyze the impact of increased Mexican tomato yields on the North American fresh tomato market. Results indicate that for the average year between 2005 and 2008, 20% higher yields would have resulted in a 15.1% increase in Mexico's tomato production and a 28.9% increase in fresh tomato exports from Mexico to the United States. As a result of higher Mexican tomato sector productivity, Canadian and US producers' shares of the US fresh tomato market would decrease and Mexico's would increase from 35.0 to 41.9%. The model shows that Mexico's share of US fresh tomato imports from both Mexico and Canada would grow from 88.1 to 90.3% as a result of the increased productivity. These results lead to the recommendation that increasing yields of this important export crop are key to maintaining and increasing the North American market competitiveness of Mexican-produced fresh tomatoes.