Introduction. Mango (Mangifera indica L.) is a fruit species with high potential for reduction of hunger and poverty in Mozambique. However, the production of this crop is currently threatened by various fruit fly species, including Bactrocera dorsalis (Hendel) and Ceratitis cosyra (Walker). Their occurrence in Mozambique needed to be assessed. Materials and methods. Fruit flies (B. dorsalis and C. cosyra) were monitored over two consecutive mango cropping seasons from September 2014 to August 2016 on 10 ha of a commercial mango orchard in Vandúzi district, Mozambique. Trapping activities were conducted using Chempac Bucket traps baited with food attractant (torula yeast). Temperature data and host phenology data were recorded at the orchard, while rainfall data were obtained from a meteorological station located 10 km away. Results and discussion. Fruit fly populations were present in the orchard over the entire trapping period (for B. dorsalis); or absent at some periods during vegetative stages of the mango (for C. cosyra). For both cropping seasons, the population of B. dorsalis peaked in January. For C. cosyra, the peak was observed in January of the first cropping season, while it was observed in November of the second season. The population of both species varied between the seasons, but in general B. dorsalis was more abundant than C. cosyra (average relative abundance index RAI = 0.814). The B. dorsalis population density had a positive relationship with minimum temperatures and mango phenology stages and a negative relationship with average temperatures, while the population of C. cosyra had a positive relationship with minimum temperatures. Conclusion. The populations of B. dorsalis and C. cosyra in Mozambique fluctuated throughout the cropping year, B. dorsalis was more abundant than C. cosyra with some periods of exclusive presence. This fluctuation seems well related to biotic and abiotic factors.