Different places look at it differently. Are your other letters ok? Most places use just it to look at the subjective comments made about you during your rotations. If you mean that your deans letter says obviously bad things about you, people will certainly ask themselves why that is. What did you not like about it?

thanks for the reply bonedoc...

my other letters are solid, but had a negative psychiatry clerkship eval which made it into the dean's letter.

shoot, if it is a negative remark from the psychopods it might help you!!! I would worry if they said you would be a great psychiatrist.

Definitely don't worry about it....

Some schools continue the Dean's Letter a "Letter of Recommendation" others consider it a "Performance Evaluation". Some deans feel obliged to put in something less than flattering so... and this really is a quote... "the letter is balanced, and the overwhelmingly good comments are believed". Whatever...
Seriously, don't sweat it... I would, however give you the following recommendations on handling this eval if it comes up in aninterview:

Don't give excuses for the evaluation.... if anything, uplay the significance of it and describe how the feedback on your "less then optimal performance" has helped you do better on your other rotations.

Just my opinion... but it always seems in your best interest to explain how a negative comment, grade, whatever... has helped you grow as a future physician than explaining why it isn't true (even if it ISNT true)

That's good advice. Thanks.