Here's a fun one...ToolTips, ListBoxes, DataSets..Oh MY! [RESOLVED,THIS BOARD ROCKS!]

[KentDMc]

This should work for you. Andy was close with the MouseHover option. I would use Mouse move, as follows. I'm assuming the name ToolTip1 for the tool tip control,

Private Sub lbxRecPart_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles lbxRecPart.MouseMove
Try
        ToolTip1.SetToolTip(lbxRecPart, dssrch.Tables("partdefinition").Rows(lbxRecPart.IndexFromPoint(lbxRecPart.PointToClient(lbxRecPart.MousePosition))).Item("PartDescription"))
 
Catch ex as Exception
End Try

The empty Catch is neccessary because if you move your mouse over an empty area of the Listbox, the lbxRecPart.IndexFromPoint will return a -1, which is not a valid datatable row index and will throw an exception, which I wanted to ignore.

I believe this will work for you. I have does similar tooltips from a dataset except mine was in a tree view.