Mackerel fillets were salted with NaCl and/or KCl to determine the most acceptable level by sensory evaluation. Additionally, the effects of ascorbic acid, vacuum packaging, and cold storages on lipid oxidation were determined for the salted mackerel fillets. Appropriate level of NaCl was ≤2%. Fifty percent replacement of NaCl by KCl reduced NaCl level with minimal impact on sensory quality. The higher the level of ascorbic acid (0–0.5%, weight basis), the higher the antioxidant effect observed with thiobarbituric acid value and peroxide value. There was no significant difference in sourness (α = 0.05) between the salted mackerel samples treated with and without ascorbic acid (0.25%). Vacuum packaging and storage at −18 °C along with ascorbic acid was most effective in retarding lipid oxidation in the salted mackerel. Vacuum-packaged sample with ascorbic acid stored at 2 °C was least oxidised, followed by vacuum packaging without ascorbic acid and then ascorbic acid without vacuum.