Display omitted •Tetragonal phase of Bismuth oxychloride (BiOCl) nanoparticles was successfully prepared via co-precipitation method at room temperature method.•Characterization of BiOCl NPs were characterized by XRD, UV-DRS, Raman, SEM and TEM techniques.•BiOCl NPs exhibit critical non-toxic properties on human erythrocytes as well as interference in the activity coagulation cascade on both PRP and PPP in human blood.•The determining the MIC and MBC of BiOCl NPs demonstrated significant inhibitory activity against pathogenic bacterial strains S.aureus and P. aeruginosa. Bismuth oxychloride (BiOCl) nanoparticles was successfully prepared via co-precipitation method at room temperature method. The structural, optical and morphological features of BiOCl NPs were characterized by XRD, UV-DRS, Raman, SEM and TEM techniques. The XRD pattern of BiOCl NPs shows tetragonal phase with an average crystalline size was found to be 23 nm. The energy band gap of BiOCl NPs is 3.5 eV with the help of UV-DRS. Raman spectroscopy was used to identify the characteristic A1g and Eg vibrational normal modes of BiOCl NPs. SEM and TEM micrographs of BiOCl NPs reveals the agglomeration of the particles with effect of reducing agent. Furthermore, MIC and MBC of BiOCl NPs demonstrated significant inhibitory activity against pathogenic bacterial strains S.aureus and P.aeruginosa. BiOCl NPs exhibit critical non-toxic properties on human erythrocytes as well as interference in the activity coagulation cascade on both PRP and PPP in human blood. As a result, the study reveals that the synthesis of BiOCl nanoparticles is very simple, inexpensive, and environmentally friendly, and that it has the potential to discover novel properties of biological activities.