, and phospholipids with ether and thioester bonds [7,8], and antibiotic mitomycin C conjugated with cholesteryloxycarbonylglycine [9]. The other group includes synthesized and characterized lipid derivatives of antiviml preparations such as acyclovir [10], phosphonoformate [11], and azidothymidine, dideoxycytidine, and dideoxythymidine known to be highly active with respect to the human immunodeficiency virus (HIV) [12]. Transformation of 7-aminobutyric acid (GABA) into 1,2-dipalmitoylglyceric or 1-acylglyceric esters allowed the concentration of this neuromediator in the brain to be increased by more than two orders of magnitude [13 -15]. Other promising directions are the modification of immunoglobulins [ 16], bacterial antigens and vaccinal preparations [17,18] that in many cases makes it possible to increase their efficiency. This work is not an attempt to consider and summarize the results of all investigations devoted to the lipophilic modification of biologically active compounds (including drugs) because these objects are rather dissimilar and differ markedly in their spectra and mechanisms of action. The purpose of this review is to demonstrate the possibilities and prospects of the lipophilic modification of biologically active compounds in the case of prostaglandins and nonsteroidal antiinflammatory drugs. The choice of these groups of biologically active compounds is mostly due to the fact