Infinite dilution binary diffusion coefficients (D 12 ) were determined for 10 R-amino acids, glycine, alanine, R-aminon-butyric acid, norvaline, valine, norleucine, leucine, isoleucine, alloisoleucine, and tert-leucine in water over a temperature range from (293.2 to 333.2) K with the Taylor dispersion technique. At 298.2 K, the literature data for the two R-amino acids alloisoleucine and tert-leucine are not available, whereas the determined D 12 values of the others are in good agreement with the data reported previously within the experimental errors of ( 2.0 %. The D 12 values for all R-amino acids studied were well-represented by two simple correlations, and the accuracies for the correlations were examined for each R-amino acid.