This work tries to analyze the determinants of the Portuguese Exports of the 18th Century; additionally, it intends to evaluate the impact of the changes made by the Marquis of Pombal. For this purpose, it uses the cointegration analysis, the spectral analysis and the synchronization analysis. This work shows that the determinants that explain the Portuguese export movements are the amounts of gold extracted from Minas Gerais plus the profits derived from the other Brazilian activities, the wine production and its unit price, and the exchange rate. The shortest cycles were those of Portuguese exports and the longest cycles were those related to the gold and wine productions. The Pombal's policies changed the synchronization of these cycles, mainlymaking the export cycle independent of the exchange rate cycle and making it also less dependent of the Brazilian gold cycle.
