The invention provides novel furoxan compounds, or pharmaceutically acceptable salts thereof, and novel compositions comprising at least one compound, and, optionally, at least one nitric oxide enhancing compound and/or at least one therapeutic agent. The compounds and compositions of the invention can also be bound to a matrix. The invention also provides methods for (a) treating cardiovascular diseases; (b) inhibiting platelet aggregation and platelet adhesion caused by the exposure of blood to a medical device; (c) treating pathological conditions resulting from abnormal cell proliferation; (d) treating transplantation rejections, (e) treating autoimmune, inflammatory, proliferative, hyperproliferative or vascular diseases; (f) reducing scar tissue or for inhibiting wound contraction; (g) treating diseases resulting from oxidative stress; (h) treating endothelial dysfunctions; and (j) treating diseases caused by endothelial dysfunctions.