With your posted sample in Cells A1:B6

Try this:
C1: (the Col_A value to find....eg 1)

Enter this ARRAY FORMULA, committed with CTRL+SHIFT+ENTER,
instead of just ENTER....in cell:
Note: Formula is in sections for readability:
D1: =IF(ROWS($1:1)COUNTIF($A$1:$A$10,$C$1),"",
INDEX($B$1:$B$10,SMALL(IF(($A$1:$A$10=$C$1),ROW($A $1:$A$10)),ROWS($1:1))))

Copy D1 and paste into D2:D5

Is that something you can work with?
Post back if you have more questions.
--------------------------

Regards,

Ron
Microsoft MVP (Excel)
(XL2003, Win XP)

"ORLANDO V" wrote in message
...
Hi,

Here is an illustrative example of my problem:

I have a list of numbers and letters. How can I lookup the value " 1 " and
return the multiple results of z, a, g ? I want to type only one formula
in one cell, although I don't mind the result being spread out over
multiple
cells. Which formula can be used?
Thanks for your thoughts on this.

1 z
2 b
1 a
3 e
4 f
1 g