Studies have been carried out to understand the specific role of the alkali charge compensator, on the luminescence properties of an alkali ion (Li+, Na+, and K+) codoped SrWO4:Eu phosphor: The oxidation state of the europium ion was found to be +3 on the basis of X-ray absorption near edge structure (XANES) measurements. This is the first report of its kind where opposite effects of Li+ ion and Na+/K+ ions on photoluminescence intensity have been observed. Li+ ion codoping enhanced the photoluminescence intensity from StWO(4):Eu3+ phosphor while Na+/K+ ion codoping did not. On the other hand; the luminescence lifetime is maximum for the Na+ ion codoped sample and minimum for the Li+ ion codoped sample. The results could be explained successfully using time-resolved luminescence, positron annihilation lifetime spectroscopy (PALS), and extended X-ray absorption fine structure (EXAFS) spectroscopy measurements. Changes in the Eu-O bond length and Debye-Waller Factor (sigma(2)) upon Li+/Na+/K+ codoping were monitored through EXAFS measurements. PALS also highlighted the fact that Lit codoping is not contributing to reduction in the cation vacancies and might be occupying interstitial sites rather than lattice positions due to its Very small size. On europium doping there is lowering in symmetry of SrO8 polyhedra from S-4 to C-6, which is reflected in an intense electric dipole transition in comparison to the magnetic dipole transition. This is also corroborated using trends in Judd-Ofelt parameters. The results have shown that the luminescence lifetime is better when the vacancy concentration is lower as induced by Na+ and Kt codoping, while the emission intensity is higher in the samples when distortion around Eu3+ is reduced as induced by Li+ codoping.