Alcoholism is one of the most frequent addictions among people. The early identification of alcohol abuse could increase the possibility of a favorable treatment outcome and reduce health care costs. Many biochemical laboratory markers of alcohol abuse have been used for several years, but each of them has clinical limitations. Recently, sialic acid (SA) has been suggested as a new potential marker of excessive alcohol consumption. In this paper, the general characteristic of SA has been given including the usefulness in the identifying of alcohol abuse. The clinical studies showed that serum and saliva sialic acid concentration was significantly higher in female and male alcoholics compared to social drinkers. It has been established also, that the serum SA level in male alcoholics was significantly increased after a short period of relapse to heavy alcohol drinking. In addition, the serum SA level was significantly decreased during an alcoholism treatment and abstinence. Sialic acid seems to be interesting biochemical marker of alcohol abuse (detecting, monitoring) with the diagnostic efficiency as good as, or even better, than the traditional markers used today.