Naphyrone, also known as naphthylpyrovalerone and O-2482, is a cathinone derivative that has been recently advertized for purchase on a number of websites. Naphyrone belongs to a new class of "designer drugs" that has emerged on the drugs abuse market and has gained popularity as the new "legal high." Legal highs have been circulating for a number of years in Europe and are becoming popular in the United States. They are affordable, widely available, legal to use and possess, and legal to supply. This review presents any available information about safety profile, clinical data, analytical profile, and legislation of this legal high, which is not legal any more. Any available information has been collected by various literature search engines and the World Wide Web. The structure of naphyrone is similar to that of pyrovalerone, a monoamine uptake inhibitor. This new designer drug does not have a long history of use, so there is little evidence of its long-term effects or on the risks from its use. Because of its similarity to other cathinone derivatives, naphyrone is likely to share the same risks, such as anxiety, paranoia, and overstimulation of the heart and circulatory system. Naphyrone was classified as a controlled drug under the UK Misuse of Drugs Act of 1971 (Amendment No. 2) Regulation 2010.