Cardiovascular diseases are the leading cause of mortality in the Western world. Among them, atherosclerosis represents one of the most common diseases in the modern society due to a common sedentary lifestyle, high-fat diet, and smoking. In the near future, a new approach could potentially improve the therapy of vascular pathologies, where to date the non-specific treatments present several limitations, such as poor biodistribution, quick elimination from the body, and undesired side-effects. In this field, nanotechnology has a great potential for the therapy and diagnosis of atherosclerosis with more and more recent and innovative publications. This review is a critical analysis of the results reported in the literature regarding the different and possible new approaches for the therapy and diagnosis of atherosclerosis.