Core level line asymmetries for liquid Al, Ga, Ge, In, Sn and Bi have been determined by numerical analysis of XPS core level spectra using Doniach-Sunjic lineshapes. For the pure liquid metals, the asymmetry parameters α have been determined as: Al2p: 0.13, Ga3d: 0.11, Ge3d: 0.09, In4d: 0.12, Sn4d: 0.13 and Bi5d: 0.12. Nozière-De Dominicis theory is used to calculate core line asymmetries from the partial electronic densities of states at the Fermi energy. Good agreement is achieved for systematic changes in both parameters. Experimental Knight shifts of liquid metals are compared with theoretical values for s-p-metals. They support the theoretical s-electron density of states (DOS) data used for calculation. Furthermore a quantitative relation between asymmetry and total DOS at the Fermi energy is proposed to explain the observed increase of asymmetry in Ga upon melting: solid: α = 0.06, liquid: α = 0.11.