The EPR spectra of microwave-prepared 70NaPO 3 :30PbO glasses containing different weight percentages of manganese ions have been studied. The EPR spectra exhibit a well-resolved hyperfine pattern at g e f f ) ∼ 2.0. Optical absorption, fluorescent emission and excitation spectra of the glasses have been examined. The absorption spectrum exhibits a peak near 500 nm and this has been attributed to the spin-allowed E 5 g → T 5 2 g transition of Mn 3 + ions. The emission spectrum shows a band at 595 nm which has been assigned to the T 4 1 g (G) → A 6 1 g (S) spin-forbidden transition of Mn 2 + ions in octahedral coordination. Concentration quenching of fluorescence was found to occur above 0.75 wt% of Mn 2 + ions. The excitation spectra exhibit four bands characteristic of Mn 2 + ions in octahedral coordination. From the observed band positions of the excitation spectra, the crystal field parameter D q and the Racah interelectronic repulsion parameters, B and C have been calculated. A structural model is proposed based on the IR, Raman and MASNMR studies according to which Mn 2 + ions are likely to occupy sites similar to Na + ions in these glasses.