<!DOCTYPE html> <html> <head> <style type="text/css"> .separator { height: 20px; background-color: green; } #min-height { min-height: 0; height: auto; margin-top: 10px; margin-bottom: 20px; } #margin-only-child { margin-top: 30px; margin-bottom: 40px; } </style> </head> <body> <div class="separator"></div> <div id="min-height"> <div id="margin-only-child"></div> </div> <div class="separator"></div> </body> </html>