The lattice dynamics of tetragonal Srsub.2VOsub.4 with a Ruddlesden—Popper-layered crystal structure was studied via Raman spectroscopy. We observed three of the four expected Raman-active modes under ambient conditions. Mode Grüneisen parameters and the implicit fractions of two Asub.1g Raman-active modes were determined from high-pressure and high-temperature Raman spectroscopy experiments. The low-energy Asub.1g Raman-active mode involving Sr motions along the c direction has a large isothermal Grüneisen parameter about seven times larger than that of the high-energy Asub.1g Raman-active mode involving apical O motions along the c direction and is, therefore, more anharmonic. The thermodynamic Grüneisen parameter is significantly smaller in Srsub.2VOsub.4 than in Srsub.2TiOsub.4 due to the smaller Grüneisen parameter of the high-energy Asub.1g Raman-active mode and other vibrational modes that still need to be identified. The explicit contribution of the low-energy Asub.1g Raman-active mode is negative, and the implicit contribution due to volume change is much larger. Both volume implicit and anharmonic explicit contributions of the high-energy Asub.1g Raman-active mode have similar positive values. The Raman experiment in the air shows that Srsub.2VOsub.4 begins to decompose above 200 °C.