Non-communicable diseases (NCDs) have become a primary health concern for most countries around the world. The aim of this research is to analyze the relevant evidence that determines the effect of socioeconomic position (SEP) on the incidence and prevalence of NCDs. A systematic literature search was performed using PubMed, Cochrane Library, and Web of Science to identify evidence regarding the relationship between income inequalities and NCDs, between 2005 and 2015. The final selection of papers was based on applied studies focusing on Organisation for Economic Co-operation and Development (OECD) countries and articles referring to three main groups of chronic diseases: cardiovascular and heart diseases, cancer, and diabetes. A final set of 47 selected studies were fully taken into account in this review. Despite significant heterogeneity in exposure and outcomes measures, overall the evidence suggests that having low SEP increases the risk of developing cardiovascular diseases (CVDs), lung and breast cancer, and type 2 diabetes. SEP is also associated with multiple NCD risk factors such as smoking and physical inactivity. Low socioeconomic status appears to have a significant consistent impact on mortality and morbidity caused by NCDs in OECD countries. Social and economic disadvantages are associated with health inequalities in terms of access to care, increased incident risk of NCDs, and early death. These findings point to the need for public health strategies and research to address socioeconomic status disparity among individuals.