Compare two worksheets and update any empty cells

Alex,

In this case, VLOOKUP won't work, because the lookup value isn't in the leftmost of the table array, this a limitation in VLOOKUP.

So, you can use INDEX/MATCH which is the best alternative.

=INDEX($D$2:$D$4,MATCH(B2,$E$2:$E$4,0))

Please find the attached file.