Enzymatic alcoholysis of fish oil can produce monoacylglycerols (MAG) rich in polyunsaturated fatty acids at atmospheric pressure and low temperature. Biocatalysis in organic solvents helps to create a homogeneous reaction system for the reactants, ethanol and fish oil. This work presents liquid-liquid equilibrium at two different temperatures (303.2 and 323.2 K) and at atmospheric pressure for two solvent-systems in the ethanolysis of fish oil: Ethanol + oil + tert-pentanol and ethanol + oil + hexane. Experimental solubility (binodal) curves were obtained by the cloud point method and tie-line composition was obtained by density and high temperature gas chromatography (HT-GC). The consistency of experimental tie line data was checked by using the Othmer-Tobias equation. The experimental liquid-liquid data were correlated satisfactorily by the nonrandom two liquid (NRTL) model for activity coefficient calculation.