Background: Klebsiella strains are opportunistic pathogens forming biofilms on many surfaces. Nowadays some resistance traits' acquirements via gene transfer mechanisms in biofilm environments cause an urgency to discover new substances targeting biofilm inhibition. Objective: The focus of this study is to examine different K. pneumoniae and K. rhinoscleromatis strains' clinical information and antibiotic resistance results according to their biofilm formation levels and to determine lemon and ginger essential oils' effects on biofilm formation. Methods: Biofilm formation of different Klebsiella strains and effects of ginger and lemon essential oils on biofilm formation were determined by Crystal Violet Binding assay. Results: Strong biofilm forming K. pneumoniae strains were more frequently observed to be isolated from blood sample. 80% of multi-drug resistant K. pneumoniae strains were strong biofilm forming and all multi-drug resistant K. rhinoscleromatis strains were intermediate biofilm formers. 170 mu l/ mL of lemon essential oil caused 48.3% (+/- 13.7) and 83.4% (+/- 7.2) decreases in biofilm formation amounts of strongest biofilm forming K. pneumoniae and K. rhinoscleromatis strains respectively. Conclusion: According to our results; multi-drug resistant K. pneumoniae and K. rhinoscleromatis strains form higher amount of biofilms and lemon essential oil might be used as a new anti-biofilm agent, targeting the inhibition of biofilm formation of K. pneumoniae and K. rhinoscleromatis strains.