In the Mediterranean, the bluespotted cornetfish Fistularia commersonii Rüppell, 1838, presents a minor socioeconomic impact and the assessment of any environmental impact requires more relevant data. The congeneric red cornetfish Fistularia petimba Lacepède, 1803, has expanded its distribution range within the basin but only small numbers have been reported to date. A total of 207 individuals of F. commersonii were collected between April 2021 and March 2022 from the Levantine coast of Rhodes and 92 more from various locations. Additionally, 13 individuals of Fistularia petimba were caught in March 2024 from the Aegean coasts of the island. We aim to assess the current progression of the population of the two cornetfish, the possible further exploitation of F. commersonii to boost the local fishing economy, their possible dietary overlaps and to add valuable biological and ecological data. In F. commersonii, male to female ratio (1:1.33) significantly departed from 1:1, with length–weight relationships exhibiting positive allometric growth. Six age groups were identified. The highest reproductive intensity was observed during summer. The onset of sexual maturity was estimated at 65.52 cm in total length (1.8 years). Longevity was estimated at 11.1 years with females growing larger than males. The exploitation rate (E = 0.47) indicated that the population is underexploited. The optimum and target fishing mortality were higher in comparison with the present fishing mortality (F = 0.48), indicating a potential for commercial exploitation of the species. For F. petimba, the sex ratio was 1:2.25. The species preys on crustaceans, followed by fish and molluscs. The finding of Vanderhorstia mertensi (Klausewitz, 1974) in the stomach content of both cornetfishes constitutes the second published record for Hellenic waters and the first for the Dodecanese Islands.