look up any word, like the eiffel tower:
 
1.
when you do a favor for a friend because he's your bro, but you expect him to do a similar favor for you in the future.

not a sexual favor though, because that would be gay.
bro #1: ok bro, i'll fix up your computer quid pro bro.

bro #2: yeah but bro like what do you mean?

bro #3: you will see.
by Maclol September 08, 2008
 
2.
A favor or advantage granted to your bro in return for goods or services. Used to make bros even.
A-"Thanks for bailing me out of that one, Bro Montana"
B-"No problem, but just to make it all Quid Pro Bro, I'm taking your sister out on a date next week"
by jrkl September 22, 2009