Export diversification – the extent to which the firm seizes export sales opportunities across different nations and/or geographic regions – is a critical element of export marketing strategy. Yet, knowledge of the export performance consequences of export diversification is lacking. Underpinned by contingency and resource dependence theories, we examine the export diversification-export performance relationship as well as critical contingencies of this link. Based on a sample of UK exporters we find that firms gain the highest export performance benefits when they simultaneously increase national and regional export diversification. Our results also show that the export diversification-export performance link is weaker when firms operate in markets that are very in dynamism. Additionally, the relationship between export diversification and performance is stronger when both resource sharing and interfunctional coordination are high. Such contextual factors provide a better understanding of the diversification-performance relationship.