Proton induced L X-ray yields from thick targets of In, Sn, Nd, Dy, Pt and Au have been measured in the energy range 1 3 MeV. Cross-sections have been derived from these thick target yields and are compared with the predictions of non relativistic PWBA, BEA and CBEA theories. The ratios O-LjaLl, o-Ljo-L~ and O-L~/aL~ are also presented.