This study assessed the effects of ε‐polylysine hydrochloride (ε‐PLH) and rosemary extract (RE) combined with slightly acidic electrolyzed water (SAEW) on the shelf life of obscure pufferfish (Takifugu obscurus) during refrigerated storage at (4 ± 1 °C). The samples were first dipped in SAEW and then treated with sterilized water (CK) and other solutions (0.2% RE [RE], 0.3% ε‐PLH [PLH], and 0.2% RE + 0.3% ε‐PLH [RE+PLH], respectively). Afterwards, microbiological, physicochemical, water migration, and sensory attributes were periodically assessed. The results showed that compared with CK and RE groups, ε‐PLH treatment could effectively inhibit microbial growth and delay the increase in total volatile base nitrogen (TVB‐N). In addition, microbial indexes, TVB‐N, thiobarbituric acid, and metmyoglobin value in the samples treated with RE+ε‐PLH were lower than those with ε‐PLH or RE alone during storage. Meanwhile, samples treated with RE+ε‐PLH exhibited the best sensory properties and no effect on color parameters. Based on the results of microbiological analysis, the shelf life of obscure pufferfish treated with RE+ε‐PLH was 14 days during refrigerated storage at (4 ± 1 °C).Practical ApplicationIn our study, the combined application of ε‐PLH, RE, and SAEW was effective to extend the shelf life of obscure pufferfish. Based on the results of total viable counts, the RE+PLH group had a shelf life of approximately 14 days. Accordingly, bio‐preservatives combined with SAEW technology have a broad application potential in the storage of obscure pufferfish.