Phospholipid hydrolysis was studied in lemon sole and haddock between -7°C and -29°C. The rate of reaction was much faster in the Gadoid. The haddock data showed evidence for a rapid first order reaction in which lecithin and phosphatidylethanolamine containing C,,:,, C,,:, and C20:5 acids were preferentially hydrolysed. The reaction proceeded to an asymptote which decreased with lowering temperature. The amount of free water available in the frozen state seemed important in these hydrolytic reactions.The relation of these findings to protein denaturation and taste panel assessment of texture are discussed.