Polycystic Ovary Syndrome (PCOS) is a complex condition characterized by reproductive, metabolic and psychological features (1). The most recent iteration of the International PCOS guidelines recommend a healthy lifestyle for effective management (2). Following a healthy diet is considered one of the first line management strategies for mitigating long-term health risks in PCOS. However, there is little evidence to support one superior dietary approach. As such, current guidelines recommend a dietary pattern consistent with population-based dietary guidelines (2). However, many women with PCOS have expressed the desire for more tailored and individualised dietary recommendations. In populations with similar health vulnerabilities, there is evidence that adherence to a Mediterranean diet (MedDiet) is inversely associated with cardiometabolic disease risk, independent of caloric restriction (3). However, the feasibility of a MedDiet in PCOS is unknown. Therefore, this study explored the feasibility of a pilot ad libitum MedDiet intervention on metabolic, hormonal and anthropometric outcomes in women with PCOS and a BMI ≥ 25 kg/m². Women with PCOS and a BMI ≥25 kg/m2, aged 18-45 years, were randomized to either an ad libitum MedDiet or a Healthy Eating (HE) control, consistent with the Australian Dietary Guidelines. The 12-week intervention incorporated fortnightly, personalized dietary consultations and tailored resources. Primary outcomes were measures of feasibility, and included items such as recruitment metrics, data collection methods, and intervention adherence. Acceptability was examined using semi-structured interviews and surveys. Independent samples t-tests were used to assess between group differences. Qualitative data from audio-recorded interviews were transcribed verbatim and analysed using framework analysis. Feasibility outcomes were reported narratively. Study promotion resulted in n=380 interested individuals; a total of n=26 were randomized to either a MedDiet (n=12) or HE (n=14) control. Data collection was mostly appropriate as demonstrated by the collection of 100% of anthropometric and biochemical data; however, only 69% of 4-day food records were returned. Participants reported the intervention as acceptable, and adherence was enhanced through individualized counselling and the provision of practical resources. At week 12, adherence was significantly greater in the MedDiet group compared to the HE control (8.1 ± 2.4 vs 4.6 ±1 .0; P=0.002). Adherence significantly improved from baseline to week 12 for both groups (MedDiet; Baseline: 3.67 ± 1.32; Week 12: 8.11 ± 2.37; P < 0.001; HE; Baseline: 3.57 ± 1.27; Week 12: 4.57 ± 0.98; P = 0.02). Our study provides valuable knowledge and preliminary evidence related to the acceptability and feasibility of a MedDiet intervention in PCOS. However, larger and adequately powered clinical trials are needed to inform clinical practice guidelines, which also consider feasibility issues identified in the present study, including participant recruitment and the collection of dietary intake data.