Paranaella, a new microcotyline monotypie genus, is erected to accommodate Paranaella luquei sp. n., parasite of gill filaments from Hypostomus sp., Hypostomus regani (Ihering) and Rhinelepis aspera Spix et Agassiz (Loricariidae) from the Paraná River, Brazil. The new genus is most closely related to Microcolyle Van Beneden et Hesse, 1863, Diploslamenides Unnithan, 1971 and Solostamenides Unnithan, 1971. From Microcolyle it differs mainly by having the genital atrium formed by a muscular ring with a concentric row of numerous elongate and straight spines; from Diplostamenides it can be distinguished by the unarmed and not differentiated cirrus and from Solostamenides it differs by the single vaginal pore and absence of larval hooks.