Processing conditions of mackerel sausage were optimized for number of washes (0, 1, 2, and 3 times) and percentages of various additives: salt (1, 1.5, 2, 3%), phosphate complex (0.1, 0.3, 0.5%), sugar (1, 2, 3%), and corn starch (1, 3, 5%). The whiteness of mackerel sausage significantly increased with increasing washing time, but the whiteness of mackerel sausage prepared with additives did not show large differences. Conditions consisting of two washes, 2% salt, 2% sugar, and 5% corn starch showed the highest hardness and gel strength, whereas the group supplemented with phosphate complex showed no considerable differences compared to the control. In the sensory evaluation, the mackerel sausage prepared with two washes compared to the control scored higher for color, aroma, and overall preference. In addition, mackerel sausage supplemented with 2% salt, 2% sugar, and 5% corn starch scored highest in overall preference. There was no significant difference in mackerel sausage supplemented with phosphate complex. Therefore, these results suggest the optimal conditions for improving the texture and sensory properties of mackerel sausage were two washes, 2% salt, 0.5% phosphate complex, 2% sugar, and 5% corn starch.