Here we present the results of a study relating molecular/electronic structure with cytotoxicity for a group of N2- alkylated quaternary β-carbolines against nine tumoral cell lines. The electronic structure of all systems was calculated at the B3LYP/6-31G(d,p) level. Statistically significant results were obtained for almost all tumoral cell lines. The analysis of the proposed pharmacophores allows detecting several atoms that can be used as targets for substitution and control of cytotoxicity.