See if this does the trick.

=COUNTA(A1:A9)-COUNTIF(A1:A9,"Yes")

"JRD" wrote:

Is there a quick and easy way of counting the number of cells that don't
contain certain text strings

For example

Column A

Yes
No
Yes
Maybe
Maybe
No
Certainly
Definately
Yes

How could I count the number of cells that don't contain the word "yes" - in
this case the answer would be 6

Many thanks