This work is aimed to study the interaction of an amphiphilic drug, promazine hydrochloride (PMZ) and two anionic surface active ionic liquids (SAILs), cholinium laurylsarcosinate [Cho][Sar] and cholinium deoxycholate [Cho][Doc] using conductivity, UV‐visible spectroscopy and fluorescence techniques. The results obtained by all three techniques indicated non‐ideal behavior and synergistic interactions between the PMZ drug and SAIL mixed systems. Further, the drug‐SAIL mixtures were used to stabilize silver nanoparticles (Ag NPs) in aqueous solution. The results of UV‐visible spectroscopy, dynamic light scattering (DLS) and transmission electron microscopy (TEM) showed that PMZ and SAILs had strong electrostatic and hydrophobic interactions which played a significant role in the stabilization of Ag NPs. The morphological analysis of the Ag NPs showed the formation of various types of aggregates controlled by the internal packing of PMZ‐[Cho][Sar]/[Cho][Doc] mixed systems. These drug‐SAIL based NPs could be used in separation and synthesis applications in nanotechnology by altering the structure of drugs and SAILs.