Measures of the HI properties of a galaxy are among the most sensitive interaction diagnostic at our disposal. We report here on a study of HI profile asymmetries (e.g., lopsidedness) in a sample of some of the most isolated galaxies in the local Universe. This presents us with an excellent opportunity to quantify the range of intrinsic HI asymmetries in galaxies (i.e., those not induced by the environment) and provides us with a zero-point calibration for evaluating these measurements in less isolated samples. We aim to characterize the HI profile asymmetries in a sample of isolated galaxies and search for correlations between HI asymmetry and their environments, as well as their optical and far infrared (FIR) properties. We use high signal-to-noise global HI profiles for galaxies in the AMIGA project (Analysis of the Interstellar Medium of Isolated GAlaxies, http://amiga.iaa.es). We restrict our study to N=166 galaxies (out of 312) with accurate measures of the HI shape properties. We quantify asymmetries using a flux ratio parameter.