Objective: It is unclear whether the cardioprotective Mediterranean diet (MedDiet) can be adhered to in non-Mediterranean populations. The aim of this study was to report preliminary results on adherence to a 6-mo ad libitum MedDiet intervention in multiethnic Australian patients with coronary heart disease, including maintenance at 12 mo. Methods: Participants (62 ± 9 y of age, 83% men) were randomized to the MedDiet (n = 34) or a low-fat diet (n = 31). Dietitian-led appointments occurred at 0, 3, and 6 mo with a follow-up phone review at 12 mo. Dietary intake was assessed via 7-d food diaries analyzed in FoodWorks8, and MedDiet adherence was measured by a validated 14-item questionnaire. Results: In the pooled cohort, the MedDiet adherence score was low at baseline (5.2 ± 2.1 of 14), with only 6.2% achieving a high score (≥9). MedDiet participants significantly improved the MedDiet adherence score compared with low-fat diet participants after 6 mo (+4.8 ± 2.7 versus +1.2 ± 2 points, respectively; P < 0.001). MedDiet participants significantly increased intake of olive oil, nuts, tomato, yogurt, legumes, and seafood and decreased intake of processed meats and added sugars compared with low-fat diet participants (P < 0.05). Maintenance of the MedDiet at 12 mo was high with 78% of MedDiet participants maintaining an adherence score ≥9; however, mean adherence score decreased by 1 ± 1.9 point (P = 0.01) between 6 and 12 mo. Conclusions: The MedDiet intervention in this pilot trial of Australian patients with coronary heart disease was well adhered to, improved diet quality, and could therefore provide a feasible alternative to a low-fat diet. Notably, improvement in adherence to the MedDiet was achieved through dietitian-led intervention and cross-cultural translation of dietary principles.