Unsupported phosphide catalysts of composition Ni2P and CoP are prepared in situ in the reaction medium from oil-soluble precursors in the course of hydrodeoxygenation of palmitic and stearic acids. The obtained catalysts are characterized by X-ray powder diffraction and X-ray photoelectron spectroscopy; they show high activity in the hydrodeoxygenation of model substrates. After 6 h of the hydrodeoxygenation reactions, the conversion of palmitic acid reaches 93 and 92% and the conversion of stearic acid is as high as 94 and 91% in the presence of nickel phosphide and cobalt phosphide, respectively. It is shown that the catalyst formed in situ can be isolated and recycled.