Thermal oxidation of porous silicon has been carried out for different durations (1 mins -10 mins), at different temperatures (400 °C-800 °C) and in different ambients (dry and wet). It has been observed that while oxidation for 10 minutes at T>600 °C causes an immediate improvement in the intensity of PL spectra of porous silicon, the characteristics is not stable. However, for shorter durations of oxidation, the PL spectra of oxidized samples remain perfectly stable even after twenty days of storage while that of the as-grown reference sample degrades considerably. Also, there is an improvement in PL intensity when the oxidation temperature is raised to 800 °C. Thus, oxidation for shorter durations can stabilize as well as improve the luminescence properties of porous silicon.