The present study concerns Atlantic mackerel (Scomber scombrus) traded as a chilled product. The study was aimed to investigate the effect of including a mixture of organic acids (citric, ascorbic, and lactic) in the icing medium employed during the fish chilled storage. To this end and according to preliminary trials results, an aqueous solution including 0.050% (w/v) of each acid was employed as icing medium; its effect on the microbial activity development in mackerel muscle was monitored for up to 13 d of chilled storage and compared to a counterpart-fish batch kept under traditional water ice considered as control. Results indicated a lower bacterial growth in mackerel muscle subjected to storage in the organic acid-icing system by comparison with control fish. Thus, statistically-significant (P < 0.05) differences between both batches for all 6 microbial groups investigated (aerobes, anaerobes, psychrotrophes, Enterobacteriaceae, lipolytics, and proteolytics) and for 2 chemical indices related to microbial activity development (total volatile bases and trimethylamine) were obtained. The surface wash caused by the melting of the ice during storage and the subsequent antimicrobial effect of such acids on skin microflora of the fish can be invoked as the main reasons for the limited bacterial growth found in the corresponding mackerel muscle. © 2012 Institute of Food Technologists®