Nontypeable Haemophilus influenzae (NTHi) is a respiratory commensal and opportunistic pathogen, which persists within biofilms on airway mucosal surfaces. In order to investigate new effective and inexpensive therapeutic approaches, we analyzed silver (Ag) and zinc (ZnO) nanoparticles (NPs) synthesized by a green approach using corresponding salt (Ag orZn nitrate) with aqueous extract of Caltropis procera leafs. The presence of phytochemical compounds in the plant leaf powder were determined qualitatively, as well as the functional bioactive groups were characterized by FTIR. Quantity and quality of Ag and/or ZnO-NPs were characterized by UV–visible wavelength scans, inductively coupled plasma mass spectrometry and nanoparticle tracking analysis. NPs could be synthesized in reproducible yields of approximately 108 particles/ml with mode particle sizes of approx. 90–100 nm. Antibacterial activity against four different NTHi strains was assessed by minimal inhibitory and/or bacteriocidal concentration (MIC and MBC) assays and biofilm formation. All strains exhibited similar resistance profiles with MIC ranging between 5×105 and 107 particles/ml. Finally, the anticancer effects of Ag and/or ZnO- NPs were challenged with HeLa cancerous cells with different concentrations. Both NPs inhibited the growth of the cancer cells significantly, in a dose dependent manner.