The self-consistent HMSA integral equation is derived for the square-well fluid and tested against Monte Carlo simulations. The phase diagram and mechanical properties are well reproduced, as well as radial distribution functions and structure factors. For narrow wells, the extent of vapour-liquid equilibria is reduced substantially, in qualitative agreement with results for the attractive Yukawa system. A recent sticky hard sphere mapping is tested to determine its validity. © 1996 Taylor & Francis Group, LLC.