Over the last decades, in many rural areas in Southern Europe, farmers have abandoned agricultural activity, especially on small-sized farms, leading to an exodus from rural areas towards urbanized ones. In this context, in the early 1980s, some Sicilian farmers introduced mango on their small-sized farms, as certain areas of Sicily are well suited to tropical and subtropical crops, but also to meet increasing consumer interest for these fruits, as they are perceived as functional foods. This paper aimed to evaluate the economic sustainability of mango and to determine whether its introduction could be considered as an alternative to traditional crops. In particular, an economic-financial analysis of mango orchards on small-sized Sicilian farms was performed by adopting a discounted cash flow approach. In order to provide as comprehensive information as possible, mango was compared with two traditional crops that have always played an important socioeconomic role in Southern Italy: wine grape and orange. Results showed a clear economic convenience for mango orchards, denoting an annual gross margin of 14,617.03 €/ha, on average 20 times higher than orange orchards and just less than 40 times higher in respect to vineyards. The higher profitability of mango was also confirmed without considering public grants for the planting phase, and by varying current sales prices and costs. However, it should be considered that the cultivation of mango could represent an opportunity for sustainable development only for certain Sicilian areas, as it is closely related to favorable pedo-climatic conditions.