Background: The resistance of microorganisms, which is quickly expanding is the most serious problem of commercial antibiotics. Thus, it seems necessary to study and know about new antimicrobial agents. Candida glabrata is the second most common cause of candidiasis after Candida albicans. Resistance to azole antifungal drugs, especially fluconazole, has been repeatedly reported in fungal infections caused by C. glabrata. As a result, the treatment of this type of fungal infection has faced many problems, and high mortality in high-risk patients admitted to the hospital, especially immunocompromised patients, has been reported many times. Objectives: This survey aimed at investigating the antimicrobial properties of lemon PEEL pineapple PEELs, and fruit extracts on some oral pathogens such as Streptococcus salivarius, Lactobacillus casei, C. albicans, and C. glabrata in vitro. Materials and Methods: In this study the soaking method was used to obtain the extracts of the selected plants, and the well method in agar was utilized to check their antimicrobial properties. Results: The results indicated that the lemon PEEL extract with a minimal inhibitory concentration (MIC) of 1. 56 mg/mL and pineapple fruit extract with a MIC of 50 mg/mL had the strongest and weakest antimicrobial properties on C. glabrata, respectively. In addition, the lemon PEEL extract had high antimicrobial properties on S. salivarius, with a MIC of 6. 25 mg/mL. Pineapple PEEL and fruit extracts demonstrated moderate antimicrobial properties on L. casei with a MIC of 25 mg/mL. Conclusion: Taking into account the antimicrobial properties of lemon and pineapple and their in vivo antimicrobial properties it may be possible to apply them as natural antimicrobial factors in the treatment of oral and dental infections and other infectious diseases.