The technological effect of antioxidant dietary fiber (AODF) from Fucus vesiculosus added to minced horse mackerel (Trachurus trachurus) during frozen storage was tested. Fish mince (FM) samples supplemented with 1 and 2% AODF were compared to AODF-free control. Dietary analysis, antioxidant capacity, total polyphenols content, ferric-reducing antioxidant power (FRAP assay), and free radical scavenging activity (by ABTS assay), water binding capacity, water holding ability, cooking yield, and sensory analyses were carried out just after freezing and during frozen storage. Samples with 1 and 2% of AODF added had lower lipid oxidation than those without AODF, and the total drip (thaw + cooking) was reduced after 3 months of frozen storage. Fish samples supplemented with 1% AODF did not have a different flavor from the control. Samples supplemented with 2% AODF had a different flavor from the control, but this did not impair palatability.