This paper presents a comparative analysis on the sensitivity of various low-wattage fluorescent lamps (FL) used in residential and commercial lighting, during voltage sags. Based on recent testing standards and utilizing a modern industrial power corrupter and advanced photometer, extensive tests were conducted for three 18 Watt FLs with different ballast types. For predefined malfunction criterion of zero illuminance condition, sag depth and duration are varied to construct individual voltage immunity curves. The different ballast technologies adopted in driving a FL seems to play a vital role in riding through in the event of voltage sag. The experimental results of tested FLs show that the lamp with electromagnetic ballast is more sensitive to voltage sags than that of the lamps equipped with electronic ballasts. Finally, when the voltage immunity levels of the tested FLs are compared with the ITIC and SEMI F47 standard, the lamp with electromagnetic ballast and CFL do not satisfy their design goals.