This study evaluated the effects of immersion duration and pineapple peel extract marination level on the physical characteristics of spent Sentul chicken breast. A completely randomized design with a 3 x 3 factorial arrangement was used. The first factor was immersion duration (10, 15, and 20 min), and the second factor was pineapple peel extract level (15%, 30%, and 45%), with two replicates per treatment combination. The observed variables were pH, water-holding capacity (WHC), instrumental tenderness response, and cooking loss. Data were analyzed using a General Linear Model, followed by Tukey and Duncan multiple-range procedures where appropriate. Immersion duration significantly affected pH, WHC, and the instrumental tenderness response (p<0.05). Marination level affected WHC and the tenderness response, while the duration x level interaction affected pH, WHC, and the tenderness response. Cooking loss was not significantly affected by either factor or their interaction (p>0.05). The reported pH values ranged from 5.77 to 6.01, WHC from 34.56% to 67.41%, the instrumental tenderness response from 13.99 to 39.86 instrument units, and cooking loss from 25.00% to 40.00%. The highest WHC was obtained after 10 min of immersion at a 30% extract level. Pineapple peel extract therefore modified several physical traits of spent Sentul chicken meat, although no single treatment combination optimized every response.