This thesis examines the relationship between working capital efficiency and firm profitability, and how this relationship is affected by economic fluctuations. In the existing literature, the relationship between working capital efficiency and firm profitability has been extensively researched. However, the impact of economic fluctuations on the relationship between working capital efficiency and firm profitability is sparsely researched. To the best of our knowledge, only Enqvist, Graham and Nikkinen (2014) have addressed the impact ofeconomic fluctuations on the relationship between working capital efficiency and firm profitability. This thesis is a replication of their study in another geographical setting, another time period and studying different types of firms. Using a sample of 2,589 firm-year observations of listed Swedish firms for the years 2000-2015, this thesis conducts multiple regression analysis to examine the relationship between working capital efficiency and firm profitability. The findings of this thesis propose that firms can enhance profitability by improving their working capital efficiency. However, the relationship between working capital efficiency and firm profitability does not appear to be significantly affected by economic fluctuations. This thesis contributes to the existing literature by further strengthening the understanding of the relationship between working capital efficiency and firm profitability. In addition, it also adds to the existing literature on the relationship between working capital efficiency and firm profitability in a Swedish context.