Introduction. A lot of plant produced essential oils, which are applied in prophylaxis and therapy of medicine. Melissa was known and used in I century BC. It produced the oil, which possess following properties: antiarteriosclerotic, anticancer, sedative, antidepression, antimigraine, antiasthmatic, antirheumatic and antioxidant. Its contain: geraniol, β-caryophyllene, geranial, thymol, neral, geranyl acetate, linalol, cytronellol, citronellal and α-humulen. It exhibited antibacterial and antifungal activity. Aim. The aim of this study was to indicate of susceptibility of yeastlike fungi to melissae essential oil. Material and methods. The strains of fungi were isolated from oral cavity from patients with candidosis. A total 23 strains of yeastlike fungi from genus of Candida albicans (22 strains), C. glabrata (5), C. guilliermondii (2), C. humicola (2), C. kefyr (3), C. krusei (5), C. lusitaniae (2), C. parapsilosis (5), C. tropicalis (6), C. utilis (1) and 9 reference strains were tested. Investigated was carried out using plate dilution technique in Sabouraud’s agar. The melissae oil (Semifarm) was dissolved in DMSO and then in aseptic distilled water. Inoculum contain 105 CFU per spot was transferred with Steers replicator upon the agar with and without essential oil (strains growth control). The concentrations of melissae oil were: 2.0, 1.0, 0.5, 0.25 and 0.12 mg/ml. Incubation was performed in aerobic conditions in temp. 37°C. Incubation of agar plates were performed in aerobic condition at temp. 37°C, at 24-48 hours. Minimum inhibitory concentration (MIC) was interpreted as the lowest concentrations of melissa oil which inhibited the growth of yeastlike fungi. Results. The dates indicated that the strains of fungi was susceptible to oil in concentrations 0.25-2.0 mg/ml. The 19 (86%) of strains from genus Candida albicans was inhibited in concentrations 0.25-0.5 mg/ml. On the same values of MIC’s were susceptible the strains of Candida albicans, Candida glabrata and Candida humicola (MIC 0.5 mg/ml). The fungi from genus of Candida kefyr, Candida krusei, Candida lusitaniae and Candida tropicalis were less sensitive. The growth of this yeastlike fungi was inhibited by concentrations of melissae oil in range 0.5-2.0 mg/ml. The oil was the lowest active towards genus Candida lusitaniae and Candida utilis. The MIC for these strains was from 1.0 to 2.0 mg/ml. From all tested genus Candida strains 11 (21%) of them was susceptible to melissa oil in range 2.0 mg/ml. Conclusions. Melissa oil was the most active towards strains of Candida albicans, Candida glabrata and Candida humicola. The lowest sensitive to oil were the strains from genus Candida lusitaniae and Candida utilis. The melissa oil characterized a high activity towards all tested strains of yeastlike fungi from genus of Candida.