Thread: maintain only first word in a cell

@Ricardo - perhaps worth ensuring that the Split is assigned to first non-blank (ie account for possibility that A1 is blank etc)

@patentprio - If :

a) the values are constants

b) blanks are real blanks (not Nulls, spaces etc)

c) number of rows specified is never excessive

you might find you can avoid iteration courtesy of a SpecialCells approach, ie:

Sub Example()
With Sheets("Sheet1")
    With .Range(.Cells(1, "A"), .Cells(.Rows.Count, "A").End(xlUp)).SpecialCells(xlCellTypeConstants)
        .Value = Split(.Cells(1).Value, " ")(0)
    End With
End With
End Sub

(you could also consider using an AutoFilter method)