Abstract The short chain aliphatic acid salts, butyrate and propionate, are effective inhibitors of histone deacetylation in chick oviduct at 2–5 mM; they also prevent the hormonal induction of the ovalbumin and transferrin genes. The less potent deacetylase inhibitor isobutyrate is correspondingly less effective in blocking egg white mRNA induction; acetate has little effect at concentrations up to 15 mM. Butyrate does not appear to alter estrogen receptor binding in the nucleus, total RNA synthesis, or protein synthesis during the early hours of treatment when its specific effects on deacetylation and egg white gene transcription are observed. In addition to preventing the induction, butyrate also causes a rapid deinduction when added to preinduced cultures; ovalbumin and transferrin gene transcription decline with a half-life of 15–30 min. The effects of butyrate on egg white mRNA induction and deacetylation are completely reversible, and mRNA induction resumes within 1 hr after removal of butyrate from the medium. These results suggest that the modification of either histones or other unidentified regulatory proteins by acetylation may play a role in the mechanism of estrogen-mediated gene induction.