The presence and characterization of Quercus petraea in the northwest of the Iberian Peninsula have been slightly studied. Although Rivas (1987) restricts his filings to the Orocantábrica Province, subsequent studies have confirmed the presence of Quercus petraea out of this place. The present investigation was undertaken to study the placing and dasometry of that specie in Galicia (Spain). Twenty-two plots with Quercus petraea as dominant specie were studied. Data about placing characteristics (location, orography, fisiografia, vegetation...) and stand variables (diametrical measurements, height, and sticks extraction for analysing of ages and growths) were checked. Basic parameters of dasometric characterization were obtained in cabinet, and subsequently the statistic analysis of multiple variables was used to study and classify stands. With both studies, we can assure that it is possible to speak of two big groups of stands: one of them clearly has typical features of hybridisation with Quercus robur and Quercus pyrenaica, that are localized near Orocantábrica Province; and the other group, that does not present those hybridisation features, is localized in the more oriental mountains. Finally, this classification in confirmed with other results as weight parameters, age, growth, etc. Consequently, the more pure stands produce data of greater maturity and a clear relation between their distribution and the classic idea of their preference by shady exhibitions is not observed in this area.