Magíster en Estudios Internacionales / The objective of this investigation is to explore the trade relationship between the U.S. and Chile within the framework of non-tariff measures. Using as its context debate between free-trade and protectionism, the question is presented as to whether or not the U.S. is misusing sanitary and phytosanitary (SPS) measures with the ulterior motive of protecting national agricultural industries and thus unfairly shifting the balance in the trade relationship with Chile. Quantitative and quantitative analysis is done to extract patterns based on the number of refusals found for different sanitary measures, particularly for fruit and seafood products. Through examination of the formation of the trading agreement between the U.S. and Chile, WTO transparency mechanisms, interviews and the study of refusal documents that describe concrete cases of rejections of agricultural imports from Chile to the U.S. for violation of SPS measures, inferences are made as to the whether or not intentions of the U.S. Food and Drug Administration (FDA) are to protect health of consumers or national industry.