Volume equations were fitted for individual trees of Pinus pinaster Ait (Maritime pine) at the Baixo Miño region in Galicia, Spain. To obtain the best volume equation the following four steps were taken: the test on statistical assumptions’ satisfaction, model ranking according to their goodness of fitting, model ranking according to their prediction accuracy, and finally, an analysis of the models prediction capacity within the range of volumetric classes. The fitted models were validated using an independent sample dataset. The selected model showed a root of mean squared errors (RMSE) of 7.77% and a bias (DA) of 0.25%. These values are notably smaller than the error and bias obtained using the fitted model from the national forest inventories for the province of Pontevedra which uses the same number of independent variables (diameter at breast height, total height and upper-stem diameter at 4 m). In addition, the proposed model was the only one that satisfied the statistical assumptions that support the regression analysis.