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The effect of increasing the rare earth ion concentration on the physical and spectroscopic properties of Nd 3+ doped sodium-lead-borate glasses have been studied for the compositions (10-x) Na 2 O-30PbO-60B 2 O 3 -xNd 2 O 3 , where x = 1.00, 1.25, 1.50, 1.75 and 2.00 mol %. Optical band gaps, cut-off wavelengths and various spectroscopic parameters (E 1 , E 2 , E 3 , F 2 , F 4 , F 6 and ξ 4 f ) have been determined from the room temperature absorption spectra. Judd-Ofelt theory has been employed to determine the intensity parameters Ω 2 , Ω 4 and Ω 6 which in turn are used to evaluate radiative transition probability (A), branching ratio (β) and radiative lifetime (τ R ) for the fluorescent level 4 F 3/2 . The Ω 2 parameter and hence the non-symmetric component of electric field acting on Nd 3+ ion is found to be highest for glass with 1.75 mol% of Nd 2 O 3 . Because of the poor resolution of hypersensitive transition, the covalency of the Nd-O bond has been characterized by the relative intensity of 4 I 9/2 → 4 F 7/2 , 4 S 3/2 . The highest covalency has been predicted for glass with 2 mol% Nd 2 O 3 . The radiative properties are found to improve with an increase in concentration of Nd 2 O 3 for the present study.