Yet another listbox question.

Try this:

Private Sub Command1_Click()
List1.AddItem Text1.text
For i = 0 To List1.ListCount - 1
    If i = List1.ListCount Then Exit Sub
    For j = 0 To List1.ListCount - 1
        If j <> List1.ListCount Then
            If LCase$(List1.List(i)) = LCase$ _
            (List1.List(j)) And i <> j Then
                List1.RemoveItem (j)
               j = 0
            End If
        End If
    Next j
Next i
End Sub