The treatment of cancer represents one of the most significant challenges currently facing modern medicine. The search for new drugs that are effective in the treatment of patients is an ongoing endeavor. It is frequently the case that the molecular target of anticancer drugs is a DNA molecule. The therapeutic effect of a drug is achieved by influencing the structure of a macromolecule or by inhibiting its function. Among the synthetic substances with potential anticancer effects, particular attention should be paid to phthalic acid imide derivatives. Three phthalimide derivatives are employed in the treatment of multiple myeloma: thalidomide, pomalidomide, and lenalidomide. Nevertheless, the search for new derivatives with a diverse range of biological activities is ongoing. In light of the above, the subject of our investigation is four non-toxic phthalic acid imide derivatives. The objective was to analyze the interaction of these compounds with DNA. The use of spectroscopic and in silico methods has enabled us to demonstrate that all of the tested analogs can act as ligands for deoxyribonucleic acid, forming non-covalent bonds with it. All four compounds tested interact with the ctDNA molecule, binding in its minor groove. The most stable complex is formed here between deoxyribonucleic acid and the C derivative, in which the -CF3 group is attached to the benzene ring. What is interesting and important, the described mechanism of action is analogous to that observed between ctDNA and thalidomide, pomalidomide, and lenalidomide.