Aims: This study investigated the antifungal activities of essential oils (EOs) extracted from anise (Pimpinella anisum) and fennel (Foeniculum vulgare) against indoor opportunistic fungi (Penicillium frequentans, Aspergillus flavus, Aspergillus niger and Chaetomium globosum) isolated from an apartment wall surfaces. The antioxidant activity of extracted EOs was examined. Methodology and results: The components of EOs were identified and quantified using gas chromatography (GC-MS). Antifungal activity, minimum inhibitory concentration (MIC) and killing potential assays of EOs were performed. EOs extracted from anise and fennel showed considerable antifungal activities against the four indoor opportunistic fungi. EO from fennel showed high antifungal activity against A. niger and C. globosum, while EO from anise showed high antifungal activity against P. frequentans and A. flavus. EOs from anise and fennel showed the same MIC values (5-8 mg/mL). EOs from anise and fennel showed high killing potential after 72 h against the indoor opportunistic fungi. The highest killing potential was against P. frequentans and the lowest killing potential was against C. globosum. Moreover, EOs from anise and fennel showed high antioxidant activities with scavenging activity after 90 min of 89.39% and 90.2%, respectively. Conclusion, significance and impact of study EOs extracted from anise and fennel could be used as natural antifungal agents against indoor opportunistic fungi.