BACKGROUND: Health-related quality of life (HRQoL) can be impacted by various environmental factors: lifestyle habits, food insecurity, social-economic status, and dietary patterns. The Mediterranean diet (MedDiet) has been associated with a healthier lifestyle and better health outcomes. The aim of this study was to determine whether greater adherence to the MedDiet was associated with better HRQoL in communities with low social and economic statuses living in two social neighborhoods, "Bairro da Rosa" and "Ingote", in Portugal. METHODS: A cross-sectional analysis was performed on 102 citizens currently receiving government social support and attending the "Health Kiosk", a community center created within the Europe Enabling Smart Healthy Age-Friendly Environments (EU_SHAFE) project enhancing educative sessions and screening by health professionals. The participants answered a 36-item questionnaire about their HRQoL (SF-36) and a 14-item questionnaire about their adherence to the Mediterranean diet (MEDAS). Spearman correlation analysis between variables and multiple linear regression models were used to estimate the effect of the baseline characteristics and MedDiet adherence on HRQoL scores (SF-36). RESULTS: No statistically significant correlation was found between MedDiet adherence and total HRQoL scores across the eight health concepts. However, age was shown to negatively influence HRQoL, whereas daily physical activity had a positive impact on health. SF-36 physical health concepts exhibited a linear trend with respect to MedDiet adherence, while emotional health concepts showed inconsistent patterns across adherence groups. Education and waist circumference influence HRQoL, with higher levels of education correlating with better quality of life and greater waist circumference being negatively associated with aspects such as energy and vitality. These findings suggest that factors beyond dietary patterns, such as physical activity, education, and body composition, play pivotal roles in shaping HRQoL in disadvantaged communities, emphasizing the need for multifaceted public health interventions.