Summary—In vivocold stress was found to induce characteristic changes in the protein synthesis pattern ofPleurodeles waltloocytes, as analyzed by two‐dimensional gel electrophoresis. The nature of the response varied with the duration and intensity of stress. After a short period of cold stress (12 h at 8°C), synthesis and intracellular distribution of polypeptides were dramatically disturbed. There occured: 1) a reduction in synthesis of several polypeptides, including two major polypeptides (54‐kDa and 47‐kDa); 2) changes in distribution of polypeptides in oocyte,iesome polypeptides (185‐ and 96‐kDa) were blocked in the cytoplasm, while other polypeptides (82‐, 74‐, 72‐ and 68‐kDa, actin and nucleoplasmin) continued to enter the nucleus, but were quantitatively reduced; 3) no changes in the distribution of two nuclear polypeptides (53‐ and 43‐kDa); 4) changes in the relative quantities of β‐ and γ‐actin and preferential migration of γ‐actin towards the nucleus. After a long period ofin vivocold stress (5 days at 8°C), we noted a partial recuperation of synthesis and nuclear migration (except for a 96‐kDa polypeptide), but a persistent perturbation at the level of actin. For more drastic stress conditions (4°C), such a recuperation of