This study examines the relationships among competitive strategies (differentiation and cost--leadership), MO (market orientation), and export performance. We used a questionnaire survey of executives of manufacturing and service companies in Peru, Brazil, Mexico and Chile and employed a structural model equation to test the hypotheses and confirmatory factor analysis to develop the underlying multi-item constructs. We find that MO mediates the implementation of competitive strategies in export performance. Additionally, differentiation strategy have a greater impact on MO than cost strategy. We conclude with implications and future research.