Rate constants over a range of temperature, enthalpies of activation, and entropies of activation are reported for the dilute acid hydrolysis of n-valeramide, isovaleramide, 3,3-dimethylbutanamide, phenylacetamide, cyclohexylacetamide, methoxyacetamide, bromoacetamide, and chloroacetamide. The rate constants of the first six amides together with those of two other alkyl-substituted acetamides taken from a previous paper are almost perfectly correlated by the Taft linear steric energy relationship. The enthalpies of activation, also, show a linear dependence on the steric parameter, Es. The results obtained for the halogeno amides indicate that the acid hydrolysis of amides may show a slight sensitivity to polar effects. © 1969, CSIRO. All rights reserved.