The corrosion efficiency of a newly synthesized cefotaxime derivative with carbon steel was studied in 0.3N sulfuric acid. The results of potentiostatic polarization measurements demonstrated that this derivative is a good corrosion inhibitor. The inhibition in both of the corrosive media was observed to be a mixed type. The potential of zero charge (PZC) at the metal–solution interface was determined for both the inhibited and uninhibited solutions to provide the mechanism of inhibition. The inhibitor formed a film on the metal surface through chloride or sulfate bridges depending upon the medium. The temperature dependence of the corrosion rate was also studied in the temperature range from (35 - 65) ◦C.