This research empirically puts to the test a series of hypotheses regarding a sample of 407 scientific-technological parks (STP) around the world.This is done using various regression models in order to analyze the impact of internalities and externalities on the performance of the STP.The most important results show the cases and conditions in which internal factors have a positive impact on performance.Given the scarce evidence available and by analyzing the aspects on which this study focuses, the work contributes significant empirical evidence to the advance of the literature on the subject.