In this study, the use of corona discharge plasma jet (CDPJ) for the improvement of hygienic quality of semi-dried mackerel pike (Gwamegi) was investigated. Different microbial contaminants, namely aerobic and marine bacteria, coliform bacteria, Staphylococcus aureus and yeasts and mold, were detected in the range 4.2-6.2 log CFU/g in Gwamegi samples. The CDPJ generated using 20 kV DC and at 58 kHz frequency was used for the treatment of Gwamegi for 0-10 min. The bacterial contaminants were inactivated in the range of 1.9-3.3 log CFU/g on the treatment for 10 min. Additionally, yeasts and mold were inactivated by 3.2 log CFU/g. The inactivation pattern fitted well to the first-order kinetics model. The CDPJ treatment for 10 min did not exert statistically significant changes (P > 0.05) in pH, moisture content, water activity, peroxide value, acid value and volatile basic nitrogen content of Gwamegi in comparison to untreated control samples. On the contrary, significant changes (P < 0.05) were noted in color and thiobarbituric acid reactive substances levels upon the CDPJ treatment. However, the CDPJ-treated Gwamegi samples displayed better sensory properties in terms of appearance, visual color, and flavor as compared to controls.