My parents will come to the US on September on Tourist Visa.
Some on told us that, your visa need to be valid for 6 months at the time of entering the US.

Their visa will expire on December 2013, does anyone here know if the visa has to be valid for 6 months when entering the US?
I am concerned if this will be a problem.
Thanks in advance.

 They won't have any problem whatsover. 

 riddle,
thank you for the prompt reply.

So, what I heard about the minimum 6month validity of US visa while entering the US is bogus?

Yup. My uncle entered the US 7 days prior to his visa's expiration earlier this month while a buddy traveled home for a month, 2 months prior to his f-1 visa expiration date. They should be fine. 

 Riddle..what visa was your uncle on? Could you please tell me how many days of stay was granted in his i-9? Need this info for my parents

Tourist visa. That's all I know. 

 Ok..thanks..even my parents are coming here just 18 days before their visa expires..I needed to book ticket but i am confused if they would be granted 6 mnths i-9 or just 18 days

 cybro, please keep us updated on your parent's i-9 information.

 My parents are coming later than your parents amol...so could you please update about i-9 of your parents

@Cybro- they will not be stampped based on the number of days the actual Visa is valid for. So, do not worry if they will be stampped for just 18 days. Even if their Tourist Visa will expire in 18 days from the time they enter the country, they will be stampped for 3 months, 4 months, 6 months or for any number of days that the POE officer deems suitable (with the maximum of 6 months at a time)