The objective of this investigation was to identify the entomofauna of mosquitoes existing in Sancti Spíritus and Villa Clara provinces, Cuba. Fluvial ecosystems were sampled which constitute the resting, oviposition and breeding sites of mosquitoes; artificial recipients in disuse, records/passive files, and existing maps in the provincial units were used. The investigation covered a period of 16 years (1999-2014). A total of 34 species of mosquitoes (49.27%) from nine genera of Sancti Spíritus province were identified, while in Villa Clara, the number increased to 43 species (62.31%) from 15genera, all this, taking into consideration the 69 species of mosquitoes recorded for Cuba. Thequalitative similarity of the entomofauna between Villa Clara and Sancti Spiritus was 60.42%. The most common species in both provinces were: Anopheles albimanus, Culex quinquefasciatus, Cx. nigripalpus ...