What version are you using? I have only needed to nest up to two levels (mainform, subform, subsubform) in Access 97, but Access 2000 Help states: "A main form can have any number of subforms if you place each subform on the main form. You can also nest up to ten levels of subforms." Limitations that I am aware of are that you can't nest a subform into a datasheet form, and also that if you have a form's view set to Continuous, it reverts to Single before inserting the subform. An sometimes useful alternative to nesting, BTW, is to use the Tab control and place a subform on different tabs. If you'd like more feedback you might try posting in the Access forum.