Penicillium italicum is an important pathogen that attacks citrus fruits. Traditionally, chemical fungicides are widely used for controlling fruit diseases, however environmental and health issues have lead to the research of safe alternatives. The efficacy of aqueous extracts from mesocarp (fibrous husk) and exocarp (outer layer) of coconut were evaluated against P. italicum development in terms of mycelial growth, sporulation and germination process. Mesocarp extracts were more efficient to control the mycelial development (82%) compared to exocarp extracts (77%). The sporulation was significantly reduced with the application of extracts from mesocarp (94%) and exocarp (93%) compared to the control treatments. The germination process was strongly affected by the application extracts. Thus, the use of these extracts could be a suitable alternative to inhibit P. italicum in citrus fruit, besides the use of these residues as a source of antifungal compounds could reduce coconut residues accumulation in the environment.