This study evaluated the operational efficiency of eight selected multinational pharmaceutical companies in the Philippines during the early implementation of parallel importation. Selected financial ratios were evaluated and the input-oriented CRS-DEA model was used in the determination of the efficiencies of the companies. Input variables used were total investment, operating expenses and cost of goods while total assets and sales as the output variables. The computed ratios of the companies served as the benchmark for the pharmaceutical industry; furthermore, ANOVA results indicated that parallel importation did not significantly affect their financial performances. This study revealed moreover, that the companies are not operating fully efficient during the study period; however, four companies operated above the mean industry efficiency of 90.60% having GlaxoSmithKline Philippines as the industry leader with an efficiency of 97.84%. Consecutively in the years 2002, 2004, 2005 and 2007 companies did not perform above the average efficiency. Multiple Regression Analysis was done to deduce a significant optimized mathematical model to predict the efficiency of a certain firm given the model. The multiple regression analysis showed that there were no at least one common variable on all the models populated for the eight companies showing that parallel importation had no effect to the efficiency scores of the said companies.