Diethylene glycol monoethyl ether (DEGME) is a hydroalcoholic solvent that gained tremendous attention in the cosmetics, food, nanoformulations, and pharmaceutical industries. Due to its physicochemical features, it has been widely used as a penetration enhancer, surfactant, and solubilizer. Among numerous tradenames defined for DEGME -- Carbitol® (by Dow Chemical Co., USA), and Transcutol® HP, CG, and P. (by Gattefossé Co., France) -- are known to be employed in pharmaceutical industries. Transcutol® CG is utilized only in cosmetics; however, Transcutol® P and Carbitol® are both used in various pharmaceutical topical dosage forms such as creams, gels, etc. Additionally, Transcutol® HP is used in all administration routes. In view of this, the application of DEGME is highlighted in the areas of industry and pharmaceutical sciences. Moreover, in this review the prominent characteristics, pharmacokinetics, and toxicity of DEGME are examined and it is suggested that DEGME is a promising solvent/solubilizer with comparable assignments to other conventional excipients.