Infection still remains a threat in maxillofacial surgery as a common complication after any surgical procedure. Despite successful application of antibiotics there are significant drawbacks and limitations such as bacterial resistance, antibiotic side effects and drug interactions. Platelet-rich fibrin (PRF) is an autologous biomaterial which consists of fibrin matrix, platelets, leukocytes and wide range of growth factors and cytokines. PRF is widely used in oral and maxillofacial surgery, regenerative medicine and may improve treatment results providing additional antibacterial activity. The aim of this study was to investigate antimicrobial activity of PRF against Staphylococcus aureus, Klebsiella pneumoniae, Pseudomona aeruginosa and Candida albicans reference cultures.