Fruit quality is highly influenced by the crop region characteristics, climate and orchard management, and may change year after year. The aim of this paper is to study the effect of the growing area on the main quality parameters of the pear cactus fruit (Opuntia ficus-indica (L.) Mill.) grown in two northwestern Argentinean provinces: Santiago del Estero and Salta. The trial was carried out in the Experimental Field "El Zanjon", an off-campus location of the Faculty of Agronomy and Agroindusties of the National University of Santiago del Estero (27 degrees 45' S, 64 degrees 18'W, 170 MASL) and in INTA Experimental Field Station "Cerrillos" (24 degrees 54'S, 65 degrees 29'W, 1100 MASL) in Salta during the 2006-2007 growing season. The climate characteristics of both sites are different. Fruits were harvested in color break and the variables analyzed were peel and pulp color, polar and equatorial diameter in order to estimate shape, pulp percentage, total soluble solid and firmness. Results showed that Santiago del Estero's fruits were significantly heavier (132.95g 6 3.69 and 113.54g 63.50 respectively) and sweeter (14.18% 6 0.14 and 13.78% 60.32) than Salta's. However, fruits from the latter were longer (1.64 6 0.02 and 1.57 6 0.03) and firmer (1.45 6 0.04 and 0.78 6 0.06) compared to the others. No significant differences were found in the other variables. Finally, in spite of the differences found, fruits from both sites had acceptable quality parameters. Nevertheless, further research should be done on the matter in order to obtain stronger results.