On Jan 14, 2:31*pm, Ron Rosenfeld wrote:
On Sat, 14 Jan 2012 09:26:02 -0800 (PST), gary wrote:
Col A has 360,000 cells.
Col B has 240,000 cells.

* * * * * * A * * * * * * * * * * * * * * * * * *B
0000000021957 * * * 0000000022002
0000000022002 * * * 0000000032002
0000000031957 * * * 0000000032003
0000000032002 * * * 0000000042002
0000000032003 * * * 0000000052002
0000000042002 * * * 0000000052003
0000000052002 * * * 0000000062002
0000000052003 * * * 0000000102002
0000000061967 * * * 0000000121996
0000000061968 * * * 0000000142002
0000000062002 * * * 0000000152002
0000000081963 * * * 0000000162002
0000000102002 * * * 0000000481994
0000000121996 * * * 0000000481995
0000000142002 * * * 0000000481996
0000000152002 * * * 0000000481997
0000000162002 * * * 0000000481998
0000000341991 * * * 0000000481999
0000000401961 * * * 0000000482000

How can I delete the cells in Col A whose contents match cells in Col
B?

Here's another macro, using the AdvancedFilter.
Please do this on a copy of your data.

You will need to set ws to the proper worksheet. *I used Sheet2.

=============================
Option Explicit
Sub PruneColA()
* * Dim ws As Worksheet
* * Dim rColA As Range, rColB As Range
* * Dim c As Range
* * Dim rCrit As Range
* * Dim i As Long
* * Dim v As Variant
Set ws = Worksheets("Sheet2")
With ws
* * Set rColA = Range(.Cells(1, "A"), .Cells(.Rows.Count, "A").End(xlUp))
* * Set rColB = Range(.Cells(1, "B"), .Cells(.Rows.Count, "B").End(xlUp))
* * Set rCrit = .UsedRange.Resize(rowsize:=2, columnsize:=1).Offset _
* * * * (columnoffset:=.UsedRange.Columns.Count + 2)
End With

Application.ScreenUpdating = False

rCrit(1).ClearContents
rCrit(2) = "=countif(" & rColB.Address & "," & rColA(2).Address(False, False) & ")0"

With rColA
* * .AdvancedFilter Action:=xlFilterInPlace, criteriarange:=rCrit
End With

rCrit.EntireColumn.Delete

On Error Resume Next
rColA.Offset(rowoffset:=1).Resize(rowsize:=rColA.R ows.Count - 1) _
* * .SpecialCells(xlCellTypeVisible).ClearContents
On Error GoTo 0

i = 0
ReDim v(1 To WorksheetFunction.CountA(rColA))
For Each c In rColA
* * c.EntireRow.RowHeight = 15
* * If c.Value < "" Then
* * * * i = i + 1
* * * * v(i) = c.Text
* * End If
Next c

rColA.ClearContents
Set rColA = rColA.Resize(rowsize:=UBound(v))
rColA = WorksheetFunction.Transpose(v)

Application.ScreenUpdating = True

End Sub
===================================- Hide quoted text -

- Show quoted text -


Your macro (using the Advanced Filter) is getting Run-time Error
'1004' of "AdvancedFilter method of Range clsss failed".

Note: I've set ws = Worksheets("Sheet1")