The paper analyses the direction and intensity of causal relationship between exporting and performance of Slovenian firms. Based on individual company data for the entire population of Slovenian firms in 1994 - 2004, the analysis confirms the existence of self-selection into exporting. Using propensity score matching methodology, we also estimate the effects of exporting on the evolution of productivity, total sales, employment, and average wages in new exporters. With respect to growth rate premia, the improvements in productivity and other performance measures are far form permanent and tend to dissipate in a couple of years after export entry. On the other hand, evidence suggests that exporting significantly improves performance of new exporters in terms of levels and that the acquired premium over non-exporters persists over medium term.