The ac susceptibility of La x Nd 1 - x F 3 single crystals, for 0 ≤ x ≤ 0.1, has been measured from 1.5 up to 40 K and their dc susceptibility for 0 ≤ x ≤ 1 has been measured from 3 up to 300 K in magnetic fields up to 0.2 T. In both susceptibilities the magnetic fields were applied parallel to the crystallographic a-axis (perpendicular to the c-axis). The effective Bohr magneton number p e f f and paramagnetic Curie temperature θ p have been obtained, using the Curie-Weiss law in the temperature range 100-300 K. Also the g-values corresponding to the five Kramers doublets in the I 4 I 9 / 2 ground multiplet of Nd 3 + ion in La x Nd 1 - x F 3 have been determined in the direction perpendicular to the c-axis, using the Van Vleck theory of paramagnetic susceptibility. The effect of the dilution of the paramagnetic Nd 3 + ions with diamagnetic La 3 + ions is also discussed.