In the U.S. you can check hospitals quality with the following web sites:

 Compare Hospitals     http://www.hospitalcompare.hhs.gov/         
 
JCAHO's web site for checking hospitals     www.qualitycheck.org 

You can order performance reports free of charge by calling
630-792-5800. (on a particular hospital)
 
International Evaluations www.jcrinc.com      1 630 268 7400     

Rate hospitals in your Zip-   http://www.leapfroggroup.org/home  
    
?America?s Best Hospitals,? by U.S.News & World Report (www.usnews.com).      

Hospital Quality   http://www.cms.hhs.gov/quality/

but how do the get similar information on hospitals in Mexico? What
are the Mexican web addresses of the various sites that provide
similar checks in Mexico?
I need answers in both English and Spanish as I do not speak or read Spanish.

For detailed information on physicians abroad, the authoritative
reference is The Official ABMS Directory of Board Certified Medical
Specialists published for the American Board of Medical Specialists
and its certifying member boards. This publication should be available
in your local library. U.S. embassies and consulates abroad maintain
lists of hospitals and physicians. Major credit card companies also
can provide the names of local doctors and hospitals abroad.

For a List of Hospitals and Doctors Abroad Please go to:

http://travel.state.gov/travel/tips/emergencies/emergencies_1195.html

and click on city of your choice in Mexico. You can view the State
Dept. website in Spanish or in English.

Also see the website of the US Embassy http://mexico.usembassy.gov/ 
which has offices throughout Mexico and will provide names of doctors
and hospitals in Mexican cities.


Medical insurance carriers such as Blue Cross/Blue Shield websites can
also be useful in finding doctors in foreign countries.

Hope this helps.

It would have helped if you had specified a particular location in
Mexico. For example, ABC hospital in Mexico City has a fantastic
reputation, though it is too expensive for locals of ordinary income.

I have strong feelings about ABC, In Dec. 1995, I fell on my face
while visiting our Mexico City home, and was in a coma for 6 days, not
really expected to live or talk again. Six days later, I woke up, and
am as onery as ever.  It turned out to be encepalitis, and though they
had no clues, treated me correctly, because MRI showed inflammation of
my brain. Six days in intensive care with 24 hour personal nurse, and
24 hour doctor in ward, plus 5 more days in hospital was around
$13,000 at the time, an exorbitant amount in the eyes of my Mexican
sister-in-law who is a retired nurse, but a bargain for my insurance
company.



There is another good one in Mexico City, and one or two in Puebla. I
can't remember their names.

Um, Guadalajara has several really good ones, because they have
several world-class medical schools.

If you get no better answers, try posting on Lonely Planet Thorn Tree
URL for Mexico.  There are many ex-pats living there who can give
recommendations for their area.