This paper investigates the oxidative regeneration of iron-based catalysts during low-pressure Fischer Tropsch synthesis (FTS), where the catalysts were operated for more than 13000 h time on stream (TOS). An iron catalyst was loaded into three separate fixed-bed reactors and then reduced using three different reducing agents, namely, syngas (Reac-Syn), hydrogen (Reac-H-2), and carbon monoxide (Reac-CO). Thereafter, the conditions were changed so that FTS was carried out over the catalysts. The temperature, gas flow rate, and operating pressure were varied with the TOS in the same way in all reactors. The activity, selectivity, and degree of conversion were measured and compared at different TOS values until the catalysts were deactivated. The spent catalysts were then regenerated in all three reactors using syngas as the only reducing agent. After the regeneration step, Fischer Tropsch (FT) runs were conducted under conditions similar to those used before regeneration, and the activity, selectivity, and conversion were measured and compared to those for the performance of the catalyst prior to regeneration. Regeneration of Reac-Syn was most effective because the conversion of the system increased from 4.66% to about 10.00% (53.40% increase). There was only a small increase in conversions in Reac-H-2 of 1.18%, while Reac-CO achieved a conversion increase of 6.25% after regeneration: The results could be useful for industrial application because industrial FT processes would require catalysts that operate for long TOS and would also require effective regeneration procedures.