The crystal structure of prehnite Ca₂(Al, Fe)(Si₃AlO₁₀)(OH)₂ from Upper New Street Quarry, Paterson, Passaic County, New Jersey, USA was determined by single–crystal X–ray diffraction. The converged structural model in the space group P 2cm [a = 4.63309(9) Å, b = 5.4839(1) Å, c = 18.5100(3) Å, Z = 2] allowed for the investigation of an ordered Si/Al distribution together with the feasible hydrogen positions inferred from the difference Fourier maps.