Background: The increase in endoprosthetic and osteosynthetic surgical treatment is associated with a simultaneous increase in implant-associated infections (surgical site infections, SSI). Biofilms appear to play a significant role in the diagnosis and treatment of these infections and heavily contaminated wounds. This article aims to provide a current overview of biofilm and its relevance in orthopedic surgery. Materials and methods: A computer-assisted literature search of MedLine (PubMed) was performed using key word combinations with “biofilm” (as of March 2017). Results: Biofilm, a polymicrobial organization and life form surrounded by a polysaccharide matrix, refers to an adaptation strategy of bacteria in unfavorable living conditions (e. g. under antibiotic therapy). Biofilms can develop after 6 h in highly contaminated wounds. In acute and chronic infections, biofilms can occur in 30–80 % of the cases. Only planktonic bacteria (high metabolic activity, cultivable) can be detected in standard microbiological cultures, biofilms, however, cannot. Molecular microscopic methods, such as fluorescence in situ hybridization (FISH), enable the detection of bacteria in biofilms. The core concepts of anti-biofilm therapy include the prevention of biofilm and early surgical debridement, followed by the local and/or systemic administration of antibiotics as well as the local application of antiseptics. Conclusions: The development of biofilm should be anticipated in strongly contaminated wounds as well as in acute and chronic infection sites. The best strategy to combat biofilms is to prevent their development. Standard microbiological culture methods do not enable the detection of biofilm. Therefore, the implementation of molecular biological detection methods (z. B. FISH) is important. Further anti-biofilm strategies are being investigated experimentally, but there are no real options for clinical use as of yet.