The handedness of lyotropic cholesterics formed by decylammonium chloride, ammonium chloride, water and chiral dopants was determined by circular and linear dichroism and, independently, by circular intensity differential scattering. From the study of the twisting power of a few dopants and from the magnetic orientation of cholesterics with long and short pitches, it is concluded that distortion of the micelles is likely to be determinant for the formation of the cholesteric phase. © 1988 Taylor & Francis Group, LLC.