The common effect of NH4+, NO3-, KH2PO4 and sucrose on the biosynthesis of galanthamine by a Leucojum aestivum shoot culture was studied. Polynominal regression models were elaborated for the description of the galanthamine biosynthesis as a consequence of variation of the investigated variables (NH4+ between 0.20 and 0.54 g/L; NO3- between 1.44 and 3.44 g/L; KH2PO4 between 0.10 and 0.24 g/L, and sucrose between 30.00 and 60.00 g/L). Optimization procedures allowed us to establish the optimal concentrations of the investigated variables and to propose the modified MS nutrient medium, with 4.50 g/L KNO3, 0.89 g/L NH4NO3, 1.25 g/L (NH4)2SO4, 0.10 g/L KH2PO4 and 60 g/L sucrose, for the galanthamine production by a Leucojum aestivum shoot culture. The proposed modified MS medium provided considerable increase of both the production yield and the relative content of the target alkaloid in the alkaloid mixture.