one way:
=IF(ISNA(VLOOKUP(A1,tableA,2,FALSE)),vlookkup(A1,t ableB,2,FALSE),VLOOKUP(A1,tableA,2,FALSE))
HTH

"James" wrote:

I have to do a vlookup, but the Table_array data is spread over two
worksheets because of the amount of data. Is this possible?