Abstract The permittivity and dielectric loss of acetyl acetone, benzoyl acetone and dibenzoyl methane have been measured at four microwave frequencies viz. 30.20, 24.50, 18.26 and 9.83 GHz and also at 1 MHz and optical frequency at 35°C, in dilute solutions of five different solvents. The permittivity and dielectric loss at different frquencies have been plotted against concentration (wt. fraction). The slopes of these straight lines have been used for the complex plane plots (a″ vs a′). The complex plane plots for these compounds are Cole-Cole arcs. The dielectric relaxation time (τ O ) and distribution parameter (α) have been calculated from these plots. Hydrogen bonding has been studied from dielectric relaxation data. The effect of various solvents on the keto-enol equilibrium has also been discussed.