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Purpose. The purpose of this in vitro study is to evaluate the effect of tea tree oil into denture liners on Candida albicans and bond strength to the acrylic denture base. Material and methods. Disc-shaped specimens were fabricated from silicone based resilient liner (Tokuyama, Molloplast), acrylic based hard liner (GC Reline) and acrylic based soft liner (Visco-gel) and tea tree oil was incorporated into liners at varying concentrations (0%-control, 2%, 5%, 8%). Candida albicans were counted by viable colony count and optical density (OD) was measured by spectrophotometer. The tensile strength to heat polymerized acrylic denture base was measured in a universal testing machine. The compliance of the data to the distribution of normality was evaluated using the Shapiro Wilk test. Two-way ANOVA, Bonferroni correction, paired sample t-test were performed (α=.05). Results. Tea tree oil addition into liners provided a significant decrease in the OD values (p <.001). The control groups of liners presented the highest colony counts, whereas increasing tea tree oil decreased the results (p <.01). According to tensile bond strength test, 8% tea tree oil addition resulted significant decrease for Tokuyama (p <,01) and Molloplast  liners (p <.05), while 2% TTO resulted significance for GC Reline (p <.001). Conclusions.  Denture liners containing tea tree oil presented lower Candida albicans colonies by the increasing amount, besides decreased the bond strength to denture bases. While using the antifungal activity of the oil, the amount of addition should be carefully selected as the tensile bond strength may be affected.