Objective: Prunus cerasifera Ehrh, belongs to the Rosaceae family, is an eight meter high tree with narrow, in some cases thorny, branches. The round red fruit which is 2-3 centimeters wide has a little wax on the surface. It is called Lushi in northern Khorasan, especially in the vicinity of Bojnourd. There, it is soaked in water and the fruit juice or the extract is used in improving hair growth and preventing dandruffs. The use of other species of sour plum in treating intestinal ailments and skin wounds has also been reported in other countries. The suggested mechanisms for the pharmaceutical properties of this fruit are as following: 1. Antifungal effects on pityrospurum ovale 2. Antibacterial effects on wound bacteria 3. Antibacterial effects on diarrhea causing bacteria 4. Improving hair growth which requires further investigations. Materials and Methods: In this study the antibacterial and antifungal effects of the methanolic extract of the fruit of Prunus cerasifera Ehrh on standard strains of Staphylococcus aureous, Escherichia coli, Pseudomonas aeroginosa, Salmonella typhi, Klebsielleae pneumoniae (all with specified PTCC) and pityrospurum ovale were investigated using broth micro dilution method and the minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC) and minimal fungal concentration (MFC) were determined subsequently. Results: The inhibitory effects of the extract on the respective microorganisms were as following: Salmonella typhi (MIC: 6.7 mg/ml , MBC: 13.4mg/ml), Escherichia coli and Pseudomonas aeroginosa (MIC: 53.68mg/ml ,MBC: 107.37mg/ml), Pityrospurum ovale (MFC: 26.8 mg/ml, MIC: 13.4mg/ml). However, Staphylococcus aureous and Klebsielleae pneumonia (MIC: 107.37mg/ml, MBC: 214.75mg/ml) were less sensitive to the extract in comparison to other strains. Conclusion: Methanolic extract of the fruit of Prunus cerasifera Ehrh had a inhibitory effect on Pityrospurum ovale and Salmonella typhi. According to our findings Prunus cerasifera Ehrh is an appropriate candidate for further investigations in order to find effective antibacterial drugs and novel treatments for dandruffs.