The purpose of this study was to evaluate the impact of adopting a Mediterranean diet on dietary cost and energy density in free-living conditions. The 12-wk nutritional intervention consisted of 2 group courses and 7 individual sessions with a dietician in a sample of 73 healthy women. To evaluate the dietary response to the nutritional intervention, a registered dietician administered a FFQ at 0, 6, 12, and 24 wk. Total daily dietary cost was calculated using a price list including all items from the FFQ. Our findings indicated that daily energy cost evaluated at wk 12 vs. wk 0 [1046 +/- 217 vs. 967 +/- 192 kJ/Canadian dollars (CAN$), respectively, P = 0.18] and total daily dietary cost (8.61 +/- 2.13 vs. 8.75 +/- 2.50 CAN$/d per participant, respectively, P = 0.58) did not change. Total daily energy density at wk 12 decreased compared with wk 0 (2.56 +/- 0.76 vs. 2.20 +/- 0.67 kJ/g; P < 0.0001). Adherence to the Mediterranean diet led to increased cost related to vegetables, fruits, legumes, nuts and seeds, canola/olive oil, whole grains, poultry, and fish (P < or = 0.01) and to reduced dietary cost for red meat, refined grains, desserts and sweets, and fast food (P < or = 0.008). In conclusion, these data suggest that adherence to a nutritional intervention program promoting the Mediterranean food pattern is not associated with increased daily dietary cost or energy cost but led to a reduction in energy density. Consequently, increased cost should not be considered a barrier to the promotion and adoption of a Mediterranean diet.