Gelatin from yellowfin tuna (Thunnus albacares) dorsal skin was optimized for adhesive strength to plywood using surface response methodology of a central composite design with a dependent variable of adhesive strength (Y, kgf/cm2) and two independent variables of gelatin concentration (X1, %) and hardening time (X2, hrs). From the above design, a maximum adhesive strength of 49.84 kgf/cm2 was obtained under the optimal treatment condition of 15.85% gelatin concentration and 25.68 hr hardening time. The adhesive strength under optimum conditions was 50.93 kgf/cm2. The adhesive strength of the tuna gelatin was shown to be superior to that of bovine and porcine gelatins which had adhesive strengths of 34.75 and 34.9 kgf/cm2, respectively.