Over the past two decades there has been a worldwide spread of blood-sucking bedbugs (Cimicidae), leading to naming them a re-emerging plague. New hosts and species have been reported and even vector-borne diseases have been associated to Cimicidae, though the latter is not fully established yet. Cimex, which is the most representative genus, is well-known for its parasitic capacity, worldwide distribution and for being considered by many authors as a man-spread plague. The healthcare impacts of Cimex invasion are being studied, but currently it is considered an alarming public health concern that has been defined by the U.S. Environmental Protection Agency as "a pest of significant public health importance". In this review, the general characteristics of Cimex, its morphology and its current geographical distribution are discussed not only in developed countries but also including nations from South America, Africa and Asia. Furthermore, we briefly describe the impact that Cimicidae has had on public health, and especially the medical importance of bites, focusing on the possible vector-borne diseases newly reported in the literature including wild species of cimicids.