The red-emitting phosphors BaTiF6:Mn4+ (denoted as BTFM) have been synthesized from HF, H2TiF6, Ba(OH)2 and KMnO4 mixed solution using a hydrothermal route. Their structure, composition and morphology were investigated. The photo-luminescent (PL) properties of the obtained BTFM products have been investigated, which exhibit broad excitation band in the blue region and sharp emission in the red region. In order to obtain the optimum BTFM red phosphor, many important factors of hydrothermal synthesis have been studied. The single red LED fabricated by combining BTFM with GaN chip shows intense red emission with the appropriate CIE chromaticity coordinates (x = 0.660, y = 0.312), and bright red light can be observed from the red LED. Therefore, this red phosphor may finds application in blue LED backlighting.