Opps that is my bad, you have to add it to the TabPage1.Controls collection not the tabcontrol itself, sorry. If there are no tabpages then you can add one to the tab control then add the controls to it.

VB Code:
  1. Dim tp As New TabPage()

  2. TabControl1.Controls.Add(tp)

  3. Dim txt As New TextBox()

  4. tp.Controls.Add(txt)

  5. txt.Visible=True

  6. txt.Location=New Point(0,0)