Alkyl esters of long chain basic aminoacids are know as cationic surfactants which have a very good solubility in water; many of them possess antimicrobial properties and are generally considered milder and less irritant than other surfactants. Long chain Nα-acyl-L- α-amino- ω-guanidine alkyl acid derivatives have recently been synthesized. Physico-chemical and antimicrobial studies of these compounds as a function of the alkyl ester or sodium salt (R), the straight chain length of the fatty acid residue (x) and the number of carbons between the ω-guanidine and α-carbxyl group (n) were carried out. Among the different aminoacid surfactant derivatives synthesized, the methyl ester of Nα-lauroyl arginine (LAM) showed higher activity of both surface and antimicrobial properties. In this study, some fundamental studies on LAM phase behavior in binary and multicomponent systems have been undertaken. The phase equilibria has been determined in the binary LAM/water and ternary LAM/water/alkanol systems. Solubilization of nonpolar compounds such as hydrocarbons has also been investigated.