Copper(I) nitrate complexes of the types L2CuNO3, L3CuNO3, and L4CuNO3 (L = tertiary phosphine) have been synthesized by reduction of copper(II) nitrate with tertiary phosphines. Infrared spectra and single crystal X-ray measurements indicate the presence of bidentate nitrate in L2CuNO3, monodentate nitrate in L3CuNO3, and ionic nitrate in L4CuNO3.The single crystal X-ray structure of nitratobis (tricyclohexylphosphine)copper(I) is reported. CuO3N(PC18H33)2 crystallizes in the monoclinic space group C2/c with a = 18.18(1) Å, b = 9.240(6) Å, c = 22.41(2) Å, and β = 96.57(5)°. The structure was solved by the heavy atom method and refined with isotropic thermal parameters to an R of 0.14. The copper atom is tetrahedrally coordinated by two phosphorus atoms and two oxygen atoms of a bidentate nitrate group. The P—Cu—P angle (140(1)°) and Cu—P bond lengths (2.29(1) Å) are the largest reported for tetrahedral copper complexes.A facile synthetic route to acetylacetonatobis(phosphine)copper(I) complexes is also described.