This work, investigates the effects of corrosion and synergistic actions of inhibitors on the fatigue properties of mild steel rods. The corrodents are saltwater and sulphuric acid while the inhibitors used are potassium chromate and 0.5M Zinc oxide. The saltwater is sodium chloride solution containing approximately 3.5% weight of solute, prepared from 97.5% Table salt; this approximates to the average salt concentration in quiet seawater. Mild steel water corroded in 0.5M H2SO4 was found to have shorter fatigue life (measured by number of cycles-to-failure) from those corroded in saltwater. Moreover, the fatigue life of specimens soaked in the corrodent in which both ZnO and K2Cr2O7 (of equal proportion) are added were observed to be longer than the fatigue life of the sample soaked in the corrodent with only k2Cr2O7. However specimens in the corrodent with only ZnO displayed the least fatigue life. These findings therefore, shows that sulphuric acid has more corrosive action on mild steel than salt water and that the corrosion inhibitor ability of K2Cr2O7 (for mild steel) is more than that of ZnO while the mixture of K2Cr2O7 and ZnO produce best corrosive inhibitor compared to those of the individual inhibitors.