Bismuth ferrite, BiFeO(3) (BFO), was synthesized in a hydrothermal process without the introduction of any metal cations, other than Fe3+ and Bi3+. For this purpose, a strong organic hydroxide was used for the precipitation of the bismuth and iron salts. With the aim to study the molar range for the production of BFO in the Bi-Fe-O system under hydrothermal conditions, the complexity of the phases appearing after the reaction was investigated. Pure-phase BFO was achieved in the case of a hydrothermal treatment after the coprecipitation of a solution of bismuth and iron salts containing an equimolar ratio of Bi3+ and Fe3+ ions. Various iron and bismuth compounds having different morphologies were achieved by changing the Bi3+:Fe3+ ratios in the reaction, but no other bismuth iron oxide phases were observed. To obtain a complete picture of the compounds, we compared the results from transmission electron microscopy with those from X-ray powder diffraction, energy-dispersive X-ray spectroscopy, and scanning electron microscopy. The dielectric properties of the pure BFO and a multiphase system were compared. The pure BFO shows a higher dielectric permittivity than the multiphase system and is comparable with the values reported in the literature.