This work aims to study the main metabolic pathways in lettuce tissues contaminated with three different pharmaceuticals: metformin MTF, carbamazepine CBZ and acetaminophen ACT . The main focus of this proteomic analysis will be the relation among stress related proteins and specific metabolic pathways regarding defence mechanisms. In order to accomplish this, previous results obtained from the direct study of enzymatic activities will be correlated with the results obtained from this proteomic analysis. This work will then contribute to improve knowledge regarding the contamination of lettuce with three largely used pharmaceutical compounds.