The objective of this work was to study the effect of seaweed (Eucheuma cottonii) our addition on physicochemical and sensory characteristics of an Indonesian-style beef meatball. Seaweed flour (SF) was added to meatball batter at 0% (CON), 2.5% (SF2.5), 5.0% (SF5) and 7.5% (SF7.5) in weight/meat weight (w/w) basis. Proximate composition (moisture, crude protein, crude fat, crude fiber and ash content), pH, cooking loss, hardness, water-holding capacity, instrumental color and sensory properties (color, texture, aroma, taste and overall acceptability) of the boiled meatballs were evaluated. The effect of seaweed our addition was very significant (P<0.01) on moisture, crude fat, crude fiber, ash, cooking loss, hardness, water holding capacity, lightness (L*), yellowness (b*) and all sensory properties, and was significant (P<0.05) on crude protein, pH and the redness (a*) of a boiled Indonesian-style beef meatball. The addition of seaweed flour at more than 2.5% resulted in darker meatballs, with less protein and fat, and a stronger seaweed aroma. The results suggest that seaweed flour could be added at 2.5% (w/w) to produce an Indonesian-style beef meatball with enhanced ber content.