The last few decades has seen many studies and articles about export dynamics – how firms and industries change when opening up for trade, how firms and industries might potentially change when opening up for trade, and how firms and industries behave according to their current trade situation. Articles have been published and used to support or justify trade agreements, while other articles have been published to impair or demote the same agreements. A unifying tendency for most of these articles is that only export behaviour is analyzed, completely excluding the behaviour of firms that import.This thesis is an attempt to shed more light on the behaviour of firms that import, by using many of the same procedures as when analyzing firms that export. Previous research has focused mainly on exporting firms, whereas this paper both describes the behaviour of importing firms, as well as exporting firms through comparisons and descriptive studies. Econometric methods are used to derive results and conclusions from a large dataset of the Norwegian industry in 2004.In the first part I do a descriptive study of the firms in the dataset, and see how variables such as wage per worker, revenues, and trade values differ between firms that do not trade, only import, only export, and both import and export. From these summary statistics it is evident that firms that only import are a substantial part of the entire selection of firms, and that they are both more numerous than firms that only export, and generating higher revenues, wages, and value added than firms that only export and firms that do not trade. This alone would be a potential reason for assessing the significance of firms that import in an economy – in lines with firms that export. Further I perform OLS regressions to find that firms that only import seem to be situated in sectors that perform well when it comes to revenues and value added. The sector affiliation is exploited further in part II.Part II examines the sector affiliation, and whether firms that import seem to situate in the same sectors. This part also gives a picture of the Norwegian industry, and why it is plausible for firms that import to locate in one sector or the other. Some of the most “well-known” Norwegian sectors are reoccurring, such as metal-production, chemicals production, and pulp, paper and cardboard production. These sectors might not necessarily have the highest number of firms, but rather stand out in total import values and total export values. In the last part I use many of the same procedures as in Eaton et al (2007), to see if firms that import behave in a different way than firms that export when it comes to the number of firms and trade partners, trade values and trade partners, and domestic sales and trade partners. By using figures one can easily compare the results between firms that import and firms that export, and I mostly find the firms that import and the firms that export to behave in a similar way. Last I see how a handful of sectors trade with different countries, to discover that import origins are often different from export destinations, which supports an inclusion of the behaviour of importing firms when performing research and making policy decisions. I have used Stata 11 to produce all the tables and figures of the thesis, while the dataset is collected by Statistics Norway.