Objective: To investigate the antifungal activity of the essential oil (EO) of Cinnamomum zeylanicum Blume (cinnamon) alone and combined with synthetic antifungal agents against Candida species. Methods: For that, it was determined the Minimum Inhibitory Concentration (MIC); Minimum Fungicidal Concentration (MFC); Fractional Inhibitory Concentration Index (FICI); microbial death curve promoted by the EO alone and combined with synthetic antifungals; action on fungal cell wall and interference of this combination on the fungal micromorphology. Results: C. zeylanicum and nystatin alone have showed MIC of 312.5 µg / mL and 64 µg / mL, respectively. When combined, there was a reduction in MIC values for both substances, decreasing to 39 µg / mL and 32 µg / mL for the EO and for Nystatin, respectively. It was verified a FICI value of 0.6024 (additivity). Under all concentrations tested, those products, alone and combined, were able to reduce the number of CFU/ mL, when compared with the control group from 30 min. It was also observed a reduction in the development of morphological structures of C. albicans cells, like pseudohyphae, blastoconidia and chlamydoconidia. When combined with miconazole, FICI values were 4.1248 (antagonism), 1.1248 (indifference) and 1.1248 (indifference), respectively, for C. albicans, C. tropicalis and C. krusei. Conclusion: C. zeylanicum was found to present activity against the Candida strains under test; this antifungal activity occurs, probably, by the action of the essential oil in the process of fungal cell wall synthesis; the combination between C. zeylanicum EO and nystatin potentiated the inhibitory effect on growth of C. albicans strains, promoting a reduction in the development capacity of cellular morphologic structures. Nevertheless, the combination of C. zeylanicum EO and miconazole was not found to be an advantageous possibility for growth inhibition of Candida spp.